A basic henge is simply a, roughly, circular space, enclosed by a ditch and bank earthwork, with an entrance, or entrances, leading to the centre. As a rule (there are, of course, exceptions), the bank is built up on the outside of the ditch – an arrangement usually regarded as being unsuitable for defensive purposes. Most henges contained various types of feature – for instance, arrangements of stones, timbers or pits.
It is generally thought that they were ceremonial centres, where people would gather together to take part in religious rituals and other communal activities. Stone circles (where a space is enclosed by standing stones), presumably fulfilling a similar role, were also constructed. Some henges combine a ditch and bank with a stone circle – including the two most famous (and magnificent), Stonehenge and Avebury, both in Wiltshire.
The archaeological term ‘henge’ is actually a back-formation from the name Stonehenge (coined in Anglo-Saxon times – meaning ‘the hanging stones’), but Stonehenge, which represents the culmination of stone circle engineering, is not at all a typical henge.
“There are four things in England which are very remarkable... The second is Stonehenge, where stones of extraordinary dimensions are raised as columns, and others are fixed above, like lintels of immense portals; and no one has been able to discover by what mechanism such vast masses of stone were elevated, nor for what purpose they were designed.”
Henry of Huntingdon ‘Historia Anglorum’ (History of the English) c.1130, translated by Thomas Forester
Stonehenge's first chronicler, Henry of Huntingdon, mused on ‘the how’ and ‘the why’ of its construction, and, nine centuries later, archaeologists are still trying to provide satisfactory answers to those two basic questions. Considerable progress has, however, been made in unravelling Stonehenge's history, and, thanks to Radiocarbon Dating, answering a third important question: ‘the when’.
STAGE 1, c.3000BC. Work on Stonehenge began in about 3000BC, with the digging of the ditch and bank – enclosing an area some 91.7 metres in diameter. Uncharacteristically for a henge, the bank was on the inside of the ditch. (There was also a low outer bank, now severely eroded by agriculture.) When new, the chalk bedrock of Salisbury Plain would have ensured the earthwork stood out boldly in the landscape. There were two entrance causeways – the main, larger, one to the north-east and a smaller one to the south. There were probably arrangements of timber posts within the henge and at the main entrance. Running just inside of the earthwork circle, there may have been a circuit of fifty-six timber posts or standing stones. These, hypothetical, posts or, more controversially, stones would have stood in the filled-in pits known as Aubrey Holes. The most popular theory in recent years has been that they held timber posts, but archaeologists of the Stonehenge Riverside Project (SRP) excavated one in August 2008, and the condition of its chalk base led them to believe that it had once supported a standing stone. Researching archive material revealed that similar crushing of the chalk had been observed, in other Aubrey Holes, during previous excavations. The SRP have gone further, proposing that the Aubrey Holes originally contained ‘bluestones’, which have generally been seen as much later arrivals at Stonehenge. (The bluestones are a heterogeneous selection of stones, apparently sourced from the Preseli Hills of south-west Wales.) Most of the thirty-four Aubrey Holes that have so far been excavated contained cremation burials.
The site seems to have stayed in this form for almost half a millennium. The ditch was neglected, and slowly filled with silt. In about 2500BC, however, Stonehenge entered a period of development during which stones were arranged and rearranged, to eventually produce the monument whose impressive wreckage remains today.
STAGE 2, c.2500BC. The stone settings built at the centre of Stonehenge fall into two categories: those made from bluestones, and those made from ‘sarsens’. Sarsens are naturally occurring sandstone slabs, and, it is generally believed, they were sourced from the Marlborough Downs, almost 20 miles to the north. In about 2500BC, a circle (30 metres in diameter) of thirty sarsen uprights (standing approximately 4 metres above ground level), topped off by a continuous circuit of sarsen lintels, was erected around a horseshoe arrangement (the open end pointing in a north-easterly direction) of five, massive, sarsen ‘trilithons’. Construction of this megalithic masterpiece would have taken an enormous number of man-hours. Once the, not inconsiderable, task of dragging the rough sarsens to the site had been accomplished, these, extremely hard, rocks were shaped and smoothed, and had joints sculpted into them using the most rudimentary of stone tools. Having levered the uprights vertical, the lintels (6 tons plus) then had to be raised (up to 7 metres above the ground), and dropped into position.
The first appearance of bluestones in the middle of the henge – indeed, their first definite appearance anywhere on site – was in a concentric double arc setting. The evidence for this placement is provided by the, so-called, Q and R Holes, which lie between the sarsen circle and trilithon horseshoe settings. There are no reliable radiocarbon dates for the double arc, but Richard Atkinson's excavations, in the mid-1950s, indicated that it was the earliest stone setting in the henge's centre. As a result, it has usually been placed a short while before the arrival on the scene, in about 2500BC, of the massive sarsens – the theory being that this rather modest bluestone arrangement (the bluestones are much smaller than the sarsens: around 2 metres long, 4 tons in weight) was quickly abandoned and removed, to make way for a much more ambitious scheme. The SRP has, however, questioned the supposed stratigraphic relationship between the bluestone arcs and the sarsens, and suggests that the settings were contemporaries – that the sarsen horseshoe, sarsen circle and bluestone arcs were all part of a single design.
As already mentioned, the SRP has also suggested that there were bluestones planted in the fifty-six Aubrey Holes centuries before their first appearance at the henge's centre. The central bluestones underwent subsequent rearrangement (of which more later), and it appears that there were about eighty of them in total. In 2009 the SRP excavated a newly discovered feature, just over a mile to the south-east of Stonehenge, adjacent to the River Avon. It had been the site of a small stone circle – about 10 metres in diameter, with an estimated twenty-five standing stones – at about the same time as Stonehenge's beginnings. The SRP have proposed that these stones were also bluestones. They suggest that the stones from both the Aubrey Holes and this newly found monument (which has been dubbed Bluestonehenge) were recycled in the centre of Stonehenge.
Though the Preseli region of south-west Wales was certainly a major source of bluestones, they are not of a uniform type, and the area of origin for all of them has not been identified. Nevertheless, to transport dozens of 4 ton stones some 150, as the crow flies, miles, over land and water, using muscle power alone, is an extraordinary achievement – in fact just too extraordinary for some authorities to accept as credible. Evidence for the alternative theory – that they were transported to the vicinity of Stonehenge by glaciers (which would certainly account for the motley mix of rock-type) – is though, at the moment, not overwhelming, and the debate continues.
Professors Timothy Darvill and Geoffrey Wainwright consider the bluestones to be Stonehenge's raison d'être. They believe that they were thought to have healing properties, and that Stonehenge was “a prehistoric Lourdes” – a place of pilgrimage, to where people would travel in the hope of being cured.
There were four isolated sarsens, known as the Station Stones, erected, just inside of the bank, on the corner points of a remarkably accurate rectangle framing the central settings.
The Avenue is cut by the A344 road. The Heel Stone stands in the foreground. Beyond the tourist walkway is the Slaughter Stone, lying in the entrance to Stonehenge.
STAGE 3, c.2400BC. Around 2400BC, the main, north-eastern, entrance to Stonehenge was restyled. The causeway was widened, by smoothing away the earthwork at the easternmost side, and an approaching Avenue was constructed. The henge's silted-up ditch was re-dug. The, now recumbent (and colourfully named), Slaughter Stone is the sole remnant of a megalithic portal into the henge. Standing in the Avenue, but not on the centre-line, about 78 metres distant from the circle centre, is a massive (35 tons) unworked sarsen, called the Heel Stone.
The whole monument is aligned on the axis of the midsummer sunrise and midwinter sunset. The tendency is to assume that it was the midsummer sunrise, as seen looking out from the centre of the stone settings down the Avenue (at the time Stonehenge was built, the sun would have risen just to the west of the Heel Stone), that was the main point of this alignment. It may be, however, that the midwinter sunset (the sun would have set between the uprights of the Great Trilithon), at the opposite end of the axis, was, at least, equally significant.
An arc of four stoneholes may be all that remains of a bluestone circle, built within the horseshoe of sarsen trilithons.
STAGE 4, c.2200BC. Round about 2200BC, bluestones were arranged in a circle, running inside the sarsen circle. The small bluestone circle inside the trilithon horseshoe, assuming there was such a structure, was restyled into an oval. According to the SRP's proposed sequence, the bluestones of the new, larger, circle had, until this time, stood in the Q and R Holes (the previous notion was that they had been removed from the site when the sarsens were installed, only to be brought back at this time). Richard Atkinson believed that Stonehenge's builders subsequently modified the oval, by removing four stones from the north-eastern end, to produce a horseshoe setting of bluestones, echoing the sarsen trilithon setting. It is perhaps the most controversial proposal of the SRP that this bluestone horseshoe did not exist. Based on the observations of Timothy Darvill and Geoffrey Wainwright, made during their 2008 excavation, it is suggested that the stones were robbed in Roman, and later, times. Mike Parker Pearson writes: “Out goes the bluestone horseshoe – there is no archaeological justification for regarding it as a separate prehistoric entity: it is more probably simply the degraded remains of the bluestone oval.” It is the remains of this final layout that is visible today.
Placed within the oval/horseshoe, near the south-western end – at the heart of the monument – was the, so-called, Altar Stone: a, dressed, greenish sandstone block, some 6 tons in weight, of Welsh origin. The Altar Stone is recumbent today, and broken in two, pinned down by stones from the collapsed Great Trilithon. Opinion is divided over whether it was originally set upright or not.
STAGE 5, c.1600BC. Many years after the bluestones had been placed in their final settings, two, inaccurate, concentric circles of pits (the Y and Z Holes) were dug, outside the sarsen circle. They never received stones, and their, apparently, half-hearted construction, around 1600BC, seems to mark the end of Stonehenge's usefulness. By this time the sarsen settings had been in place for almost a millennium, and it is possible that some may have already fallen.
Built to inspire awe, Stonehenge was clearly a sacred place where rituals took place. Beyond that generalisation, however, its purpose and meaning have long been the subject of speculation. The SRP has found evidence supporting Mike Parker Pearson's theory that Stonehenge was but one component of a larger ritual complex. Durrington Walls, Britain's largest henge (around 480 metres in diameter), and its smaller (around 85 metres in diameter) companion, Woodhenge, lie in a little valley less than two miles to the north-east of Stonehenge. In 2005, a metalled roadway (Durrington Avenue) connecting the Southern Circle of Durrington Walls to the River Avon was discovered. Whereas Stonehenge and the Avenue were aligned on the axis of the midsummer sunrise and midwinter sunset, the Southern Circle and roadway were aligned on the axis of the midwinter sunrise and midsummer sunset. The timber structure of the Southern Circle was linked, via Durrington Avenue, the River Avon and Stonehenge Avenue, to the stone structure of Stonehenge. Professor Parker Pearson believes that the, short-lived, wooden structure represented the land of the living, whilst the permanent stones of Stonehenge represented the realm of the ancestors. Symbolic journeys between to the worlds of the living and the dead could be made via the monuments' ceremonial Avenues and the river.
Nobody ever lived at Stonehenge, but the remains of houses have been found at Durrington Walls:
“The Durrington Avenue and Southern Circle were the main components of a ceremonial complex, later encircled by the henge bank and ditch, which formed the focus of a very large settlement whose house floors have been well preserved beneath colluvium... The discovery of houses within, underneath and outside Durrington Walls suggests that a large area of the valley in which the henge lies was probably covered in dwellings... It is likely that these dwellings were lived in by the builders of the Southern Circle and Stonehenge, and latterly the Durrington Walls and Woodhenge henges. Radiocarbon dates of occupation and use in the 26th century BC can be matched by identical dates for construction of the sarsen circle and trilithons at Stonehenge, suggesting that these same people also built Stonehenge in that century.”
Stonehenge Riverside Project: ‘Summary Interim Report on the 2006 Season’
The houses are squarish and have floorplans similar to the famous stone built, late Neolithic, houses at Skara Brae, in the Orkneys. At Durrington Walls, where the houses would have been, predominantly, made from timber, none of the fixtures have survived, but there are slots in the chalk floor where the wooden furniture was located. The settlement may not, however, have been permanently occupied. The nature of the debris found in the houses, and the shortage of workaday implements, has led Professor Parker Pearson to suggest that it was occupied during a midwinter festival, when people from all over the region would congregate to take part in great feasts, and ceremonies involving the Durrington Walls/Stonehenge complex. The professor's theories are persuasive – he may be right – but, unfortunately, we can never know with certainty. As Samuel Pepys, having found the stones of Stonehenge “as prodigious as any tales I ever heard of them”, confided to his diary in 1668: “God knows what their use was”.
The Swindon Stone, on the right, alongside the road at the northern entrance to Avebury.
The Barber Stone is foreground left. In the middle distance are stones of the southern inner circle. The pair of stones furthest right mark the southern entrance.
Avebury is about 17, crow flying, miles north of Stonehenge. Even today its earthwork, enclosing an area 350 metres in diameter, is impressive. When built the bank would have been something like 27 metres wide at the base and 6 metres high. The ditch was 9 metres deep and some 14 metres wide at the top, tapering to less than half that at the bottom. There were entrance causeways at the north, south, east and west. These breaks in the earthwork were, millennia later, adapted to carry the roads serving the village of Avebury, which inhabits the henge. Some of the massive (in the region of 60 ton) stones that acted as portals can still be seen. Both remain at the southern entrance. One, the Swindon Stone, stands at the northern entrance. According to, antiquarian, William Stukeley, the Swindon Stone's partner (a stone “of a most enormous bulk”) fell down, and broke, in 1722: “... we saw three wooden wedges driven into it, in order to break it in pieces.” One fallen stone marks the eastern entrance. Nothing remains at the western entrance. The portal stones were part of a ring of standing stones which ran around the perimeter of the enclosed area. This outer circle (at the latest count) comprised 101 stones. 30 can be seen today. There were two inner stone circles, each roughly 100 metres in diameter. The southern one had about 30 stones set around the central Obelisk. Five stones from the circle still form an impressive arc. The Obelisk is no more. However it was sketched by William Stukeley in 1723. To the west of the Obelisk are a line of 6 smallish stones – the remains of the, so called, Z Feature. There were 9 stones in the line originally, and 3 other stones (one at the northern end, two at the southern) are known to have extended the setting, eastwards and inwards, towards the Obelisk. The eastern side of the southern circle has never been fully investigated. To the south of the circle stood the Ring Stone. All that remains is a stump, but according to William Stukeley the stone (“not of great bulk”) had “a hole wrought in it”. Excavation has shown that the Ring Stone had replaced a larger stone which originally stood in the same hole. Only four stones from the northern circle can still be seen. It is possible that this circle wasn't actually a circle at all. It may have been a horseshoe – open on the south. Either way, at its centre was the Cove – three stones set in a U-shaped arrangement – which opened towards the north-east (in the general direction of midsummer sunrise). Two of the three stones still exist. In 2003, work was carried out to straighten the leaning stones, which were in danger of collapse. The mighty back-stone, which projects almost 4½ metres above ground, was found to extend more than 2 metres (perhaps as far as 3 metres) below ground. It could weigh up to 100 tons. OSL dating indicated that the stone was erected c.3000BC. All the stones at Avebury are sarsens – found locally, on the Marlborough Downs, a couple of miles to the east. They have been left in their natural state – not smoothed or worked to shape, as happened at Stonehenge. It seems, though, that, in the circles, the stones were set so that their, naturally, smoothest side faced inwards.
The chronology of Avebury is far from certain, but the order in which it seems that the various components may have been constructed is, perhaps, somewhat surprising. The above mentioned OSL date suggests that, at about 3000BC, the Cove was the first structure erected. The inner stone settings – the southern circle and Obelisk, and the northern circle/horseshoe around the Cove – were probably next, beginning around 2900BC. Radiocarbon assays, from antlers found on the ditch bottom, tend to place the earthwork in the period around 2550BC. The perimeter stone circle was probably erected after the bank and ditch were finished. Other odd stones were also later additions – including the Z Feature and Ring Stone, which were supported by chalk blocks taken from the ditch. Two avenues of standing stones were built (say 2400BC) approaching the western (Beckhampton Avenue) and the southern (Kennet Avenue) entrances of the henge.
Although the Avebury sarsens were not worked to shape, they were selected for their natural shape. This is particularly apparent from the stones which can be seen on Kennet Avenue (most of which were re-erected by Keiller). Sarsens naturally occur in two forms: columnar and broader, lozenge-type, shapes. On Kennet Avenue these shapes alternate along the length of the rows, and, also, opposing stones are of contrasting shape. There seems to be general agreement that columnar stones are symbolically male and lozenges female.
Avebury's stones seem to have remained unmolested until the early-14th century. Then, perhaps because they were offending Christian sensibilities, some were tipped into pits and buried. In 1934, Avebury was bought by a rich archaeologist, Alexander Keiller (of the ‘Dundee Marmalade’ family). His intention was to restore the site to something like its former glory. He cleared away trees, undergrowth and rubbish. He removed fences, old barns, and derelict cottages. Indeed, he wanted to rid the henge of all buildings, and used to have houses demolished as they became vacant. Keiller's investigations along the western half of the outer circle brought to light several buried stones. He re-erected them in their original positions. Where he found a stonehole, but the stone itself was missing, he had the position marked with a concrete plinth. Trapped by one of the buried stones was a human skeleton. It was dated, by coins, to the early-14th century, and was identified as a barber-surgeon, by virtue of a pair of scissors and a medical-looking probe or lance. At the time it was thought he had been accidentally crushed whilst assisting with the burial of the stone, but a more recent recent examination of the skeleton seems to indicate that this was not the case. Maybe he was pinned to the ground and died of suffocation, or maybe he simply died and, for some reason, was buried with the stone. At any rate, the re-erected stone is known as the Barber Stone. Keiller had begun excavating the southern circle (discovering the Z Feature) when his work was interrupted, by the outbreak of the Second World War, in 1939. In 1942 the National Trust bought Avebury. When the war ended, Keiller's poor health prevented him from resuming his excavations, though he continued to live in Avebury Manor until his death, in 1955. In 2003, at least 15 buried stones, in the eastern half of the outer circle, were located by geophysical survey, but there are no plans to follow Keiller's example and re-erect them.
In fact, the stones which were buried were the lucky ones:
“I have heard the minister of Aubury [Avebury] say those huge stones may be broken in what part of them you please without any great trouble. The manner is thus: they make a fire on that line of the stone where they would have it to crack; and, after the stone is well heated, draw over a line with cold water, and immediately give a smart knock with a smyth's sledge, and it will breake like the collets at the glasse-house.”
John Aubrey ‘Natural History of Wiltshire’ written 1656–86
By the time William Stukeley visited Avebury (1719–24) the destruction of the stones was in full swing:
“Just before I visited this place, to endeavour at preserving the memory of it, the inhabitants were fallen into the custom of demolishing the stones, chiefly out of covetousness of the little area of ground, each stood on... The custom of thus destroying them is so late, that I could easily trace the obit of every stone; who did it, for what purpose, and when, and by what method, what house or wall was built out of it, and the like.”
Kennet Avenue connected Avebury to a stone circle, almost 2 miles to the south, whimsically called the Sanctuary. William Stukeley witnessed the destruction of this monument in 1723–24. Beckhampton Avenue has been so thoroughly erased that doubt about its very existence began to creep in. John Aubrey hadn't registered it, and there was a feeling that it may have been a figment of William Stukeley's imagination. Stukeley (who was ordained in 1729) became convinced that the Druid religion was the antecedent of Christianity. Further, he developed the idea that:
William Stukeley's: “A Scenographic view of the Druid temple of Abury in north Wiltshire, as in its original”.
“The whole temple of Abury [Avebury] may be considered as a picture, and it really is so... When I frequented this place, as I did for some years together, to take an exact account of it, staying a fortnight at a time, I found out the entire work by degrees. The second time I was here, an avenue was a new amusement. The third year another. So that at length I discover'd the mystery of it, properly speaking; which was, that the whole figure represented a snake transmitted thro' a circle; this is an hieroglyphic or symbol of highest note and antiquity.”
‘Abury, a Temple of the British Druids, with some others, Described’
The Sanctuary, at the end of Kennet Avenue, formed the serpent's head, and Beckhampton Avenue formed the tail. No remains of Beckhampton Avenue were apparent however, and, since Stukeley did tamper with his earlier findings to make them fit his theory, it was no wonder that some archaeologists were sceptical that Beckhampton Avenue had ever existed. Stukeley was vindicated, however, when archaeologists found traces of it in 1999. Where, and how, it terminates is not known. Stukeley was “sufficiently satisfied” he knew where it ended – making it about the same length as Kennet Avenue. He was also sure, for two reasons, that its terminus wasn't a stone circle. Firstly, because it was the tail of the snake, and to have a circle would be “absurd”. His second reason is, rather more convincingly, that there was “not the least report of such a thing among the country people”.
In his diary entry for 15th June 1668, Samuel Pepys wrote:
“In the afternoon come to Abebury [Avebury], where, seeing great stones like those of Stonage [Stonehenge] standing up, I stopped, and took a countryman of that town, and he carried me and shewed me a place trenched in, like Old Sarum almost, with great stones pitched in it, some bigger than those at Stonage in figure, to my great admiration: and he told me that most people of learning, coming by, do come and view them, and that the King did so: and that the Mount cast hard by is called Selbury [Silbury Hill], from one King Seall buried there, as tradition says. I did give this man 1s [one shilling].”
Standing over 30 metres high, with a diameter of about 160 metres, Silbury Hill is often said to be the largest man-made prehistoric mound in Europe.
There have been three major excavations of Silbury Hill, which is less than a mile to the south of Avebury, since Pepys' time. In 1776 a vertical shaft was driven vertically through the mound; in 1848 a horizontal tunnel was dug to its centre; and between 1968 and 1970 further excavations, along the line of the 1848 tunnel, were carried out. Despite the local tradition mentioned by Pepys, no burial has been found. In 2000, the backfilling of the 1776 shaft collapsed, leaving a large hole in the Hill's summit. Further investigation showed that there were also voids in the other diggings' backfill, and that there was a danger of the whole monument collapsing. Essential works to stabilize the Hill were carried out in 2007–8, giving archaeologists access to its interior. New datable material was found, and, additionally, archive material was reassessed. A, perhaps surprising, picture of Silbury Hill's chronology has emerged. It began in about 2450BC, as an unimposing gravel mound, less than a metre high and 9–10 metres in diameter. The site then, seemingly, underwent virtually continuous development, evolving through many stages, for between 55 and 155 years, at which point work stopped, leaving the Silbury Hill we know today. (Well not quite – it appears that, in the early-11th century AD, a spiral pathway was dug into the hillside, the top was levelled-off, and a timber fortification was erected on the summit.)
“One is that the winds issue with such great violence from certain caverns in a mountain called the Peak, that it ejects matters thrown into them, and whirling them about in the air carries them to a great distance... The third is at Chedder-hole, where there is a cavern which many persons have entered, and have traversed a great distance under ground, crossing subterraneous streams, without finding any end of the cavern. The fourth wonder is this, that in some parts of the country the rain is seen to gather about the tops of the hills, and forthwith to fall on the plains.”
Deer antlers, used as picks or rakes, were left at the bottom of the ditch. Radiocarbon dating of these tools indicate that Stonehenge's ditch was dug sometime between 3000BC and 2920BC. Unfortunately, not all of Stonehenge's features have provided dateable samples.
Aubrey Holes are named after, the antiquarian, John Aubrey, who, in 1666, appears to have detected five of them. The plan below shows the ditch (in yellow), bank and Aubrey Holes.
The most intensive period of investigation at Stonehenge was between 1919 and 1926, carried out by William Hawley. In a press-release of January 2001, English Heritage notes:
“Hawley excavated a large proportion of the eastern part of the monument, in a programme of work that is considered over-vigorous by today's standards.”
Hawley dug 32 Aubrey Holes – it was, apparently his assistant, Robert Newall, who gave the pits that name. They were numbered in a clockwise direction – Aubrey Hole 1 being at about 2 o'clock, adjacent to the south end of the main entrance. Numbers 1–30, 55 and 56 were excavated under Hawley. Richard Atkinson (in association with Stuart Piggott and J.F.S Stone) excavated numbers 31 and 32 in 1950.
Hawley initially believed that the pits had held stones, but later, apparently influenced by the excavations at nearby Woodhenge in 1926–27, changed his mind in favour of timber posts. Atkinson (who directed excavations, and reconstruction work, at Stonehenge from 1950 to 1964) considered the Aubrey Holes to be, simply, pits.
Mike Parker Pearson is at pains to point out that one of his colleagues at the 2008 excavation, Julian Richards, was not convinced there was unequivocal evidence that the Aubrey Hole under investigation, number 7, had once held a stone.
Excavations have, so far, found – in the Aubrey Holes, but also in the ditch and in the bank sides – 63 cremation burials (according to Mike PP), the majority being of adult males. Mike Pitts has estimated that there might be as many as 240 cremations – making Stonehenge the largest known prehistoric cremation cemetery in Britain.
A sample of charcoal, associated with a cremation in an Aubrey Hole, was radiocarbon dated around 1952 – early in the history of the technique – and the resulting date-range(3020–1520BC) is too wide to be very helpful. In 2007, however, samples of remains from three cremation burials, which had been kept by Salisbury & South Wiltshire Museum, were radiocarbon dated. The oldest sample was from Aubrey Hole 32 (excavated 1950). Its date (3030–2880BC) places cremations at Stonehenge from its very beginning – they had previously been believed to be later additions – and confirms the, already generally accepted, notion that the Aubrey Holes belong to Stonehenge's earliest stage. The other two samples were from the ditch (excavated 1954), and their dates (2930–2870BC and 2570–2340BC) show that cremation burials were deposited at Stonehenge over a period of at least 500 years. So few burials over such a long period might tend to suggest that the dead individuals belonged to a ruling elite. (In addition, two fragments of non-cremated human skull recovered from the ditch have produced dates of 2890–2620BC and 2880–2570BC.)
In 1935, a number (59 according to Mike PP) of cremations, unearthed by William Hawley during the 1920s, were reburied (in sandbags, and accompanied by a commemorative plaque) in Aubrey Hole number 7. This Aubrey Hole was reopened in August 2008, and the remains removed for further examination.
The Stonehenge Riverside Project was a collaborative effort by five university teams, under the direction of Mike Parker Pearson (University of Sheffield), with codirectors Josh Pollard (University of Bristol), Julian Thomas (University of Manchester), Kate Welham (University of Bournemouth), Colin Richards (University of Manchester) and Chris Tilley (University College London). Between 2003 and 2009 the SRP undertook extensive fieldwork in Stonehenge's environs, and carried out a reappraisal of material produced by earlier archaeologists.
There is a complex of postholes – pits that once held timber posts – within the henge, between the centre and the southern entrance, and also at the main entrance. Only one posthole has provided a dateable sample (a piece of pig-rib), and that produced a date around 2500BC (2580–2460BC), which is, of course, centuries after Stonehenge's beginnings, and is actually about the same time that construction of the surviving stone settings started. However, where excavations have revealed overlaps of postholes and stoneholes, the postholes have always been the earlier feature. There are hundreds of postholes, and it seems reasonable to suppose that they span the history of the site – perhaps, in some cases, predating the henge itself.
Richard Atkinson, who gave the Q and R Holes their designation, thought the setting (which is known to have been of bluestones because of chippings found in some of the holes) formed a full circle. However, only an eastwards facing arc is clearly evident, though there are also isolated stoneholes in a couple of places on the same orbit. Possibly the setting was abandoned before it was finished, or perhaps later soil disturbance has effectively erased some of the evidence. At any rate, the original form of this setting is not certain, but there does appear to have been some kind of entrance arrangement at the north-east, opposite which there may have stood a large upright stone. (William Hawley found a worn axe-head, from Cornwall, at the bottom of a large pit in which the stone may have stood.) It may be that the large stone is still at Stonehenge, having been resited, now known as the Altar Stone (of which more later).
Plan of the sarsen settings at the centre of Stonehenge. The uprights shown black are those standing today. The orbit of the Q and R Holes lies between the trilithon horseshoe and the circle.
In 1993–94, English Heritage funded a project to reassess the results of 20th century excavations at Stonehenge. As part of the work, an extensive programme of radiocarbon dating was carried out. The fruit of this labour was published as ‘Stonehenge in its Landscape’ in 1995, and, in effect, it is this work that the SRP has now refined and developed. At any rate, it was thought that there was one deer antler sample relevant to the construction of the circle, and three relating to the trilithons. The spread of dates derived from the samples, however, was very large. Not only that, it seemed as though the circle had been built before the trilithons were erected, which, on purely practical grounds, seems unlikely. More recent research, by the SRP, demonstrated that two of the samples, which had been thought to relate to the erection of the trilithons, actually belong to later work. Eliminating these two samples led the SRP to place the construction of both the trilithon horseshoe and the circle during the period 2620–2480BC (whereas, If all the samples are taken into account, the estimated date for the trilithons shifts to 2440–2100BC.)
A small excavation was carried out, in the spring of 2008, by Timothy Darvill and Geoffrey Wainwright (who were not part of the SRP), in an attempt to find material that would date the bluestones' placement in the Q and R Holes. No meaningful dating evidence was produced, but the excavation convinced Darvill and Wainwright that Atkinson had been wrong about the stratigraphic relationship between the Q and R Holes and the sarsens. As a result, they, and subsequently Mike Parker Pearson (director of the SRP), came to the conclusion that the bluestone double arc (represented by the Q and R Holes) was part of the same phase of construction as the sarsen settings. As a result the SRP scheme dates the erection of the trilithon horseshoe, the bluestone double arc and the sarsen circle, in that order, to the period 2620–2480BC.
The two rejected samples were found in a pit that Richard Atkinson believed was the ramp used to erect one of the uprights (Stone 56) of the Great Trilithon. The SRP have, however, convincingly shown that, whatever its purpose actually was (that remains uncertain), this large pit (it has never been excavated to its fullest extent) was not used as an entry-ramp, but it was dug in 2440–2100BC – long after the trilithons had been raised (2620–2480BC). Indeed, the pit is so deep and in such close proximity to the Great Trilithon, that it may have, eventually, been the cause of the latter's collapse.
Six radiocarbon dates were derived from samples found in one Q Hole. They covered the range from 3370–3090BC to AD1480–1640. However, the samples had suffered from a process called ‘bioturbation’, meaning they had been moved from their proper position in the layers of soil by the action of worms and other burrowing creatures, so no reliable figure for the digging of the Q Hole could be arrived at. In fact, only one of the dates (2460–2200BC) was in the right ballpark and, in the immediate aftermath of the excavation, this date, ‘around 2300BC’, received much media coverage. Darvill and Wainwright later collaborated with Mike Parker Pearson to produce the SRP chronology for Stonehenge.
Mostly dolerite, but also rhyolite, volcanic and calcareous ash, and sandstones.
Trilithon: three stones – two uprights topped by a lintel.
Whilst the sarsen uprights in the circle tip the scales around 25 tons, the largest trilithon upright weighs almost twice that. Three of the five trilithons are standing today (one of these was re-erected in 1958, having collapsed in 1797).
The first version of Stonehenge lasted from the digging of the ditch and bank in 3000–2920BC, to the arrival of the sarsens, in 2620–2480BC. There are no radiocarbon dates available for the newly discovered stone circle, but it can be loosely dated from two flint chisel arrowheads, recovered from the packing of two stoneholes, to around 3400–2500BC.
The lintels were secured atop the uprights by ‘mortice and tenon’ joints.
Left: Tenon on top of an upright.
Right: Mortice in a fallen lintel.
The lintels in the circle were also locked together by a tongue and groove joint. Presumably, such sophisticated joinery was commonplace in timber structures.
Of the thirty uprights in the circle, seventeen are now standing, and six lintels are in place.
The stone would have been moved forward on rollers and tipped into its hole. Some holes appear to have been given a sloping entry-ramp to ease this process. The projecting end would then be levered up, and the stone hauled vertical with ropes (probably using an A-Frame to increase leverage). The cavity was then packed with rubble.
There is no evidence to show how the lintels were raised. If an earthen ramp had been used, traces would have been found. One popular idea is that the lintels were placed on a log platform next to the uprights. The stone was then levered up, and other logs pushed (at right angles to the previous logs) under it. This was repeated, until the stone had been raised to a sufficient hight that it could be pushed across and located on the uprights. As with every other aspect of the operation – easier said than done!
The, now ruined, Great Trilithon (at the apex of the horseshoe) once stood over 7 metres tall – more than 2 metres higher than the sarsen circle.
There is no absolute evidence that the stones that stood at Bluestonehenge were actually bluestones. The shape and size of the stoneholes rule out the possibility that they were sarsen slabs. The identification of them as bluestones is based on the imprints that some of them have left behind.
The removal of the stones from Bluestonehenge is dated by an antler pick discarded at the bottom of an emptied stonehole, to 2460–2270BC. This is corroborated by the date obtained from another pick, 2469–2286BC, which had also been left on site after the stones' removal.
The Station Stones were placed, more or less, on the same circuit as the, by then filled in, Aubrey Holes. Two of them – they are undressed sarsens – remain. One (identified as Stone 93), though still erect, is just a 1 metre high stump. The recumbent Stone 91 is 3 metres long. Stones 92 and 94 are gone, but originally they were partially buried by low earth mounds – referred to as the North and South Barrows. There are no radiocarbon dates available for the Station Stones. All that can be said for certain is that they post date the Aubrey Holes (shown yellow on the plan).
Based on the similarity between William Hawley's description of a surface he had uncovered beneath the South Barrow, and their own observations of house floors at the nearby site of Durrington Walls, the SRP believe that the remains of D-shaped buildings underlie the North and South Barrows.
The SRP dates the Station Stones c.2500BC, i.e. in the same time bracket as the construction of the sarsen settings (and, in their opinion, the bluestone arcs) at the henge's centre. If, however, sighting across the diagonals of the rectangle was an important part of the function of the Station Stones, then they would certainly have to predate the sarsen settings (though not necessarily the bluestones), which would have blocked the view.
There are theories concerning the astronomical significance of every feature of Stonehenge – that the positioning of each pit, post, stone and entrance was intentional, creating alignments that were important to the beliefs of the builders. Aubrey Burl, however, makes a rather more prosaic suggestion regarding the Station Stones “... a plausible interpretation is that they created a template whose intersecting diagonals established a centre for the forthcoming sarsen ring that the world knows as Stonehenge. If so, it might seem no more than prehistoric idleness that failed to withdraw them when the circle was completed.”
The Avenue is almost 3 kilometres long. From the henge's entrance, the first 500 metres runs dead straight, in the direction of the midsummer sunrise, before turning east and then dropping southwards to the River Avon. It is difficult not to see the Avenue's approach to Stonehenge as a processional route. It is bounded on both sides by outer ditches, about 20 metres apart, and inner banks. Though none are now evident, there may have been standing stones, at intervals, along the banks – it seems that holes were discernible in the early 1720s, when, the antiquarian, William Stukeley investigated Stonehenge. The SRP discovered that the north-east entrance to Stonehenge is at the end of two parallel natural ridges, some 200 metres long, that just happened to align with the midsummer sunrise/midwinter sunset axis, and that these ridges lie under the banks of the Avenue (prompting speculation that this natural phenomenon was the reason that Stonehenge was built where it was).
Sarsen and bluestone chippings – the debris of stone-dressing – found beneath its banks indicate that the Avenue post dates the construction of the henge's central settings, and this is confirmed by dates obtained from four samples (of antler and animal bone) recovered from the Avenue's ditches. These dates have usually been interpreted to suggest that construction of the Avenue spanned several centuries (the straight section from the henge's entrance being built first), but the SRP have concluded that the whole thing was built in 2500–2270BC, and then the silted-up ditches were recut in 2290–2120BC.
Although the Avenue's earthworks are visible from the ground in the vicinity of Stonehenge itself, ploughing has virtually erased them along much of its length. In 1973 its route had been traced to within 150 metres of the Avon. At the end of their 2008 season, archaeologists of the SRP were investigating alongside the river when they discovered, not the parallel ditches of the Avenue that they were hoping for, but an intriguing curved ditch. Excavations had to wait until the following year. It turns out that the Avenue terminates at the monument which has been dubbed Bluestonehenge. Bluestonehenge began life as a stone (presumed to be bluestone) circle. After the stones were removed (presumably for use at Stonehenge), a henge, some 30 metres in diameter, was constructed.
The SRP dates this re-digging of the ditch (which has a shallower and wider profile than the original) 2560–2140BC (obtained from a piece of animal bone).
In the plan below, the yellow shaded area is where the entrance to the henge was widened by tipping that section of the original bank into the ditch. After the infilled ditch was excavated, in the 1920s, the rubble was apparently left out – in effect recreating the bank, and giving the erroneous impression that the Slaughter Stone was erected at the edge of the entrance. The plan of Stonehenge from 1810 shows its relative position before excavation.
The Slaughter Stone is a large (some 28 tons), worked, sarsen slab. Next to it are holes where two other stones once stood (D and E). Radiocarbon assays of two antler samples found in Stonehole E provided a date of 2480–2200BC. The SRP places the raising of the Slaughter Stone and its two companions prior to this – in Stage 2 (which they date 2620–2480BC), the same stage of construction as the central sarsen settings – and suggests that Stones D and E were removed in Stage 3 (which they date 2480–2280BC), when the Avenue was built. There is, however, some evidence to suggest that two of the portal stones were present and still standing during the 17th century, but when the antiquarian William Stukeley investigated Stonehenge in the early-1720s, only the fallen Slaughter Stone remained.
In 1620, King James I instructed the architect Inigo Jones to investigate Stonehenge. The result was a book, ‘Stone-Heng Restored’, in which Jones presented his vision of how the monument originally looked. He gave the Slaughter Stone a partner – but he also showed three entrances and six trilithons. Nevertheless, after Jones' death, his protégé John Webb wrote (‘Vindication of Stone-Heng Restored’) that: “... he [Jones] hath described in his Draught two Stones ... these were the two parallel Stones that stood upon the inside of the Trench, at the Entrance from the North-East ...” Below, Inigo Jones' imagined plan of Stonehenge.
In John Aubrey's plan, ‘The Ichonographie of Stoneheng as it remaines this present yeare 1666’, the positions of the Slaughter Stone and its colleague are both shown, though whether they were upright is not indicated. Incidentally, Jones envisaged a matching pair of uprights on the outside of the ditch, and Aubrey marks the position of one on his plan (below).
The A344 road cuts across the Avenue, just avoiding the Heel Stone. Stoneholes show that two other monoliths (B and C) once stood between it and the henge's entrance causeway.
In 1979 a stonehole was found (97) which suggested that, at one time, the Heel Stone had a partner that was, at some stage, removed and a ditch dug around the, now solitary, Heel Stone. Rodney Castleden comments: “I can offer no explanation at all for the removal of stone 97: as far as I know, no one has yet offered a plausible explanation. The pair of Heel Stones made a perfect ritual doorway for the midsummer sun ...” There is, though, a plausible explanation (one favoured by the SRP). Evidently Stonehole 97 was cut into the infill of an earlier, larger, hole. It may well be that this was the Heel Stone's natural resting place. It was first erected into Stonehole 97, but was later moved into its present position.
Aubrey Burl suggests that the Heel Stone was first erected long before the henge was dug. He argues that it was one in a series of stones marking the line of an ancient trackway, and was later integrated into the monument.
The bluestone oval comprised twenty-three uprights – the four at the north-eastern end might, or might not, have been removed by Stonehenge's builders. It isn't certain how many uprights formed the circle, though it could have been sixty. Many of the bluestones are now gone. Aubrey Burl writes:
“The remaining stones exist in untidiness. A few stand, some tilt, more are fallen and a few are eroded almost out of sight.”
However, it does seem as though it was the choicest bluestones that had been employed in the oval (they are all dolerite), and they were shaped and polished, whilst those in the circle were left rough. According to Aubrey Burl:
“The circle bluestones, like leftovers, were hastily and carelessly set up as though they had been no more than a method of using up the remaining stones.”
Some bluestones display evidence of their use in previous settings. For instance, Stone 68 (shown left) has a grove down one edge which could well match up with a projecting tongue on, the broken and covered, Stone 66. Both of those stones were reused in the oval. Two stones from the circle (Stone 36 and Stone 150) have mortice holes carved in them, so it seems that at one time they were the lintels of bluestone trilithons.
There are dateable samples associated with these later bluestone settings: one of antler and one of animal bone from the large circle, and one of antler from the oval. Additionally, the orbits of the Q and R Holes and the possible small bluestone circle were cut by a large pit dated 2470–2210BC. A stone of the oval was subsequently set into the filling of this pit. As a result, the estimated dates of construction are: 2270–2020BC for the large bluestone circle, and 2210–1930BC for the bluestone oval.
The Z Holes are about 3.7 metres outside the sarsen circle. The Y Holes about 11 metres. The existing stones would have prevented the use of a rope to mark out the circles, and, as a result, the accuracy of the layout is poor. Presumably the intention was to have thirty pits in each circuit (matching the sarsens), but the work appears to have been abandoned. One antler sample from Z Hole 29 and three from Y Hole 30 (both of these holes are in the north-east of their circuits) have provided radiocarbon dates. Rather than simply being abandoned tools, these antlers would seem to be deliberately deposited offerings. The constructors of the henge's ditch, back in c.3000BC, had deposited animal bones, but not just any animal bones – they were venerable relics, having been collected many years before the henge's construction. Similarly, one of the antler samples from Y Hole 30 and the sample from Z Hole 29 are significantly older than the other two from Y Hole 30. Taking this into account, the proposed date for the digging of both the Y Holes and the Z Holes is 1680–1520BC.
Apparently, one of the Z holes was never dug. Aubrey Burl suggests that this may have been because its intended spot was covered by a fallen sarsen.
Durrington Walls has been severely damaged by ploughing, and is crossed by the A345 road.
Three entrances have been detected: at the north-west, at the south (facing Woodhenge) and at the south-east. In 1967, ahead of improvements to the A345, excavations found the remains of two timber-post circles. The smaller, two ringed, Northern Circle and, adjacent to the south-eastern entrance, the 40 metre diameter, six ringed, Southern Circle.
Woodhenge was discovered in 1925, by one Squadron Leader Insall (who spotted it from his aeroplane). Its bank and ditch surrounded an arrangement, 44 metres in diameter, of six, concentric, timber-post rings. (The timbers were later replaced by a smaller, rectilinear, setting of stones). The remains of a child with a cleft skull were found near the centre of the henge. At the time of the discovery (1926), it was thought the child (probably a girl about three years old) may well have been a dedicatory sacrifice, but the bones were destroyed during the Blitz, so a modern reassessment is not possible. Woodhenge had one entrance, at the north-east.
John Aubrey's interest in Avebury began in January 1649, when he came across the monument, by chance, whilst out hunting. In 1663 Aubrey became a Fellow of the Royal Society (founded 1660). His opinion that Avebury did “much exceed” Stonehenge came to the attention of the Society's patron, King Charles II, and resulted in Aubrey giving the king a guided tour:
“... I shewed him that stupendious Antiquity, with the view whereof, He and his Royal Highness, the Duke of Yorke, were very well pleased.”
Aubrey is best known today for a collection of biographical titbits known as ‘Brief Lives’, but, as Aubrey Burl points out:
“... he was, without question, the first great English fieldworker and archaeologist.”
John Aubrey's archaeological notes, which he had pieced together to make a book, ‘Monumenta Britannica’, were only published in 1980 (Vol.I) and 1982 (Vol.II).
Only the stones visible today are shown.
Harold St.George Gray directed excavations at Avebury in 1908,09,11,14 and 22. This photograph, showing his workers, vividly illustrates the ditch's original depth.
The henge is now known as Avebury because that is the name of the village. This wasn't always the case, however. It used to be called Waledich – probably from the Anglo-Saxon‘weala-dic’, meaning ‘ditch of the Britons’. According to Aubrey Burl it was still being called Wall-dyke in the 19th century. Though the village of Avebury has Anglo-Saxon roots, its spread into the henge itself is relatively recent. Andrew Reynolds, in a paper appearing in the ‘Archaeological Research Agenda for the Avebury World Heritage Site’ (February 2001), writes:
“From the evidence available, it can be argued that early medieval settlement began immediately to the southwest of the henge monument, probably during the 6th century, and most likely comprised a single farmstead. By the early 9th century the settlement had moved northwards and eastwards, up to the west entrance of the henge itself. During the 8th or perhaps the 9th century an elliptical plan-form developed, with evidence for further enclosures to the north and south, which perhaps included the precinct of a minster church (the present-day St James). In the 9th century the settlement was arguably replanned on a major scale and the minster church, either rebuilt or newly built, leaving the fragments of Anglo-Saxon sculpture which survive today incorporated into the late Anglo-Saxon church and the present south porch. The extent of the proposed 9th century settlement indicates speculative urban development, but by the time of the Domesday Survey the rural character of Avebury, which has persisted into modern times, was established.With the exception of property boundaries, settlement lay largely without the henge until the post-medieval period, but extended and expanded westwards and northwards in the form of Avebury Trusloe and the growth of Avebury village itself.”
Stukeley wrote that the, prostrate, Obelisk was:
“... of a vast bulk, 21 feet long, and 8 feet 9 inches diameter; when standing, higher than the rest.”
The five remaining stones of the southern circle, with the smaller stones of the Z Feature behind. Concrete plinths mark empty stoneholes.
William Stukeley's sketch of the Cove. He says that the missing, northern, wing fell down in 1713 (no doubt it was broken up for building material):
“They told me it was full seven yards long, of the same shape as its opposite, tall and narrow.”
Incidentally, Stukeley, mistakenly, though that, apart from their different central features, the southern and northern circles (“temples”) were identical – each having an outer ring of 30 stones and a, concentric, inner one of 12.
Optically Stimulated Luminescence dating: a technique in which the length of time that has elapsed since a mineral was exposed to daylight is determined.
Sarsens, in their natural state, are found scattered on the ground surface. Indeed, they were also known as Grey Wethers, because of their resemblance to a grazing flock of sheep. The tops of the stones are rougher than the undersides due to weathering.
There are a couple of possibilities worth mentioning. Firstly, it may be that the massive earthwork, the remains of which we see today, replaced an earlier, much smaller, ditch and bank. Excavations have revealed the profile of a smaller bank buried under the final bank. Aubrey Burl argues that this small bank was merely a guideline for the main earthwork. Secondly, stoneholes might indicate that the original plan was for a third setting, to the north of and inline with the southern circle and northern circle/horseshoe, but that this was abandoned in favour of the encircling bank and ditch.
The skeleton was thought to have been destroyed in an air-raid during World War II. In 1999, however, it was found in the Natural History Museum. Examination showed that the man had a healed sword-cut on his head. It has been speculated that he may have been wounded during Edward I's campaigns in Wales or Scotland. The man's broken hip bones, it is suggested, had occurred naturally, with the passage of time, and were not caused by crushing.
A group of techniques (magnetometry, resistivity and ground-penetrating radar are commonly used in archaeology) utilised to detect and identify features below the ground surface.
Stukeley names those he knew to be responsible for destroying the stones. In a reference to the use of fire to smash them, he writes:
“One Tom Robinson the Herostratos of Abury, is particularly eminent for this kind of execution, and he very much glories in it.”
Stukeley mocks Tom Robinson in the above drawing.
Both John Aubrey and William Stukeley realised that monuments such as Stonehenge and Avebury were religious centres built before the Roman occupation. Since the only information they had about pre-Roman Britain was from the writings of the Romans themselves, it was reasonable to conclude that these monuments were Druid temples. As it happens, this conclusion was a couple of thousand years awry.
“This Overton-hill, from time immemorial, the country-people have a high notion of. It was (alas, it was!) a very few years ago crown'd with a most beautiful temple of the Druids. They still call it the sanctuary... It had suffer'd a good deal when I took that prospect of it, with great fidelity, anno 1723, which I give the reader in plate XXI [below].”
By the end of 1724, all the stones had been removed, and the land ploughed over. The site was found, from Stukeley's description, in 1930. When it was excavated, not only were there the holes from the two, concentric, stone circles sketched by Stukeley (the diameter of the outer circle is about 40 metres), but there were also holes for six, concentric, rings of timber posts. Interpreting the building sequence of this monument continues to keep archaeologists entertained. Some interpreters have suggested the postholes are the remains of roofed buildings (the same has been said of Woodhenge's posthole rings), but it is probably fair to say that most archaeologists today are inclined to the view that they held free-standing posts. Possibly the posts had timber lintels, or perhaps they were decorated in the fashion of totem-poles.
In a preface, appearing in ‘Stonehenge. A temple restor'd to the British Druids’ (published 1740), Stukeley writes:
“My intent is (besides preserving the memory of these extraordinary monuments, so much to the honour of our country, now in great danger of ruin) to promote, as much as I am able, the knowledge and practice of ancient and true Religion; to revive in the minds of the learned the spirit of Christianity, nearly as old as the Creation, which is now languishing among us; to restore the first and great Idea of the Deity, who has carry'd on the same regular and golden chain of Religion from the beginning to this day; to warm our hearts into that true sense of Religion, which keeps the medium between ignorant superstition and learned free-thinking, between slovenly fanaticism and popish pageantry, between enthusiasm and the rational worship of God, which is no where upon earth done, in my judgment, better than in the Church of England. And seeing a spirit of Scepticism has of late become so fashionable and audacious as to strike at the fundamentals of all revelation, I have endeavoured to trace it back to the fountain of Divinity, whence it flows; and shew that Religion is one system as old as the world, and that is the Christian Religion; that God did not leave the rational part of his creation, like the colony of an ant-hill, with no other guide than instinct, but proportion'd his discoveries to the age of the world, to the learning, wisdom, and experience of it; as a wise parent does now to his children. I shall shew likewise, that our predecessors, the Druids of Britain, tho' left in the extremest west to the improvement of their own thoughts, yet advanc'd their inquiries, under all disadvantages, to such heights, as should make our moderns asham'd, to wink in the sunshine of learning and religion. And we may with reason conclude, there was somewhat very extraordinary in those principles, which prompted them to such a noble spirit as produced these works, still visible with us, which for grandeur, simplicity and antiquity, exceed any of the European wonders.”
Predecessor of modern Salisbury, built, by the Normans, within the defensive earthwork of an Iron Age hillfort.
John Aubrey (‘Monumenta Britannica’):
“No history gives any account of this hill; the tradition only is, that King Sil or Zel, as the countrey folke pronounce, was buried here on horseback, and that the hill was raysed while a posset of milke was seething.”
An article in ‘Antiquity’ (Volume 81, Number 311, March 2007), by Alex Bayliss, Fachtna McAvoy and Alasdair Whittle, states:
“The new programme for dating Silbury Hill was conceived from the outset within a Bayesian statistical framework. This allows the chronology of the monument to be formally estimated, using an explicit statistical methodology, from both the radiocarbon dates and the stratigraphic sequence revealed by archaeological excavation. This approach was introduced for the construction of archaeological chronologies more than a decade ago, and the impact of its routine application is beginning to become apparent.”
‘Bayesian statistics’ are named after, Nonconformist minister and mathematician, Thomas Bayes (1702–1761), a pioneer in the field of probability theory.
Dated by pot sherds and a coin, of King Æthelred (the Unready), of c.1010. It doesn't seem unreasonable to suppose that the Hill's summit was fortified as a result of the Viking activity that characterizes Æthelred's reign (see: Return of the Danes), indeed, the ‘Anglo-Saxon Chronicle’ records a battle in the locality (“at Kennet”), in which English forces were defeated by Vikings, in 1006.
Mike Parker Pearson has summarized the findings and conclusions of the Stonehenge Riverside Project in “Stonehenge: Exploring the Greatest Stone Age Mystery”, 2012.