Diocletian. Archaeology Museum, Istanbul.

Diocletian’s accession, on 20th November 284, is the event which is said to mark the end of a half-century-long period of disruption and distress for the Roman Empire, known as the ‘third-century crisis’, and to usher-in a half-century-long (until the death of Constantine, 22nd May 337) period of recovery and major reform. Indeed, Edward Gibbon, in his influential masterwork, The History of the Decline and Fall of the Roman Empire (published, in six volumes, 1776–88) wrote:

Like Augustus, Diocletian may be considered as the founder of a new empire.
Chapter 12

Just a couple of years after his accession, however, Roman Britain broke away from Diocletian and, for a decade, operated as an independent empire.

The death of Carinus, in 285, had left Diocletian as sole ruler of the Roman Empire. Previously, Carinus had governed in the West, whilst his brother, Numerian (into whose shoes Diocletian stepped), had governed in the East.[*] Diocletian must have seen the benefit of this division of responsibility, since he quickly raised a trusted younger colleague, Maximian, to the rank of Caesar. Maximian took charge in the West, whilst Diocletian returned to the East. Maximian’s immediate challenge was that:

… in Gaul Helianus and Amandus had stirred up a band of peasants and robbers, whom the inhabitants call Bagaudae, and had ravaged the regions far and wide and were making attempts on very many of the cities … [Maximian] marched into Gaul and in a short time he had pacified the whole country by routing the enemy forces or accepting their surrender. In this war Carausius, a citizen of Menapia, distinguished himself by his clearly remarkable exploits. For this reason and in addition because he was considered an expert pilot (he had earned his living at this job as a young man), he was put in charge of fitting out a fleet and driving out the Germans who were infesting the seas.
Aurelius Victor Liber De Caesaribus §39
… Carausius, who, though of very mean birth, had gained extraordinary reputation by a course of active service in war, having received a commission in his post at Bononia [Boulogne], to clear the sea, which the Franks and Saxons infested, along the coast of Belgica and Armorica [i.e. along the northern coast of Gaul] …
Eutropius Breviarium Ab Urbe Condita IX, 21


The town wall at Verulamium (St Albans), built by c.270. The core is exposed today – originally it was faced in dressed flint. When built, the wall was about 10 feet thick at the base, about 15 feet high, and backed by an earth bank. It was over 2 miles long – enclosing an area of around 200 acres. The wall was topped by a walkway and parapet, and had two large and, probably, three small gateways. Except where it ran alongside the river Ver, there was a ditch, some 90 feet wide and 20 feet deep, in front.
Although mentioned by neither Aurelius Victor nor Eutropius, it is reasonable to assume that Britain too was subject to attack by Germanic raiding parties. Most major, and many small, towns seem to have received masonry defensive walls during the 3rd century.[*] In The Decline & Fall of Roman Britain (Second Edition, 2004), Neil Faulkner avers:
Many [towns] were close to the sea or on navigable rivers. Their improved third-century defences would certainly have made them secure against small Germanic war-bands, and, if provided with flotillas and garrisons, they would have guarded access routes into the hinterland. There is no reason to assume the deployment of regular Roman troops. The municipalities were certainly authorised – and most probably ordered – to construct town-walls. It would be rather surprising if they were not at the same time expected to make some provision for local self-defence, perhaps by creating a militia, perhaps by hiring mercenaries; town-walls mean little without men on the parapets.
Chapter 4
Further, the construction of a system of coastal forts, known as the ‘Saxon Shore’ forts (of which more later), took place in the late-3rd century.
An inscription at Rome (ILS 615) indicates that Diocletian acquired the title Britannicus Maximus before the end of 285. Carinus had previously held the same title, which signals that he, or an officer he delegated with the task, carried out a successful campaign in Britain. Possibly Diocletian simply took over Carinus’ title without having a legitimate claim of his own. Perhaps a campaign initiated by Carinus was brought to a successful conclusion after his death, and so Diocletian claimed the credit. Diocletian apparently dropped the title later, which might suggest that he owed it to a victory achieved by Carausius.

In spring 286 Maximian was elevated to full emperor (i.e. Augustus) status. Diocletian remained the senior partner, however, assuming the title Jovius (after Jupiter), whilst Maximian took that of that of Herculius (after Hercules).

… [Carausius] having captured numbers of the barbarians on several occasions, but having never given back the entire booty to the people of the province or sent it to the emperors, and there being a suspicion, in consequence, that the barbarians were intentionally allowed by him to congregate there, that he might seize them and their booty as they passed, and by that means enrich himself, assumed, on being sentenced by Maximian to be put to death, the imperial purple, and took on him the government of Britain.
Eutropius Breviarium Ab Urbe Condita IX, 21
But by this nefarious act of brigandage, first of all the fleet which once guarded the Gauls was abducted by the pirate [Carausius] as he fled, and then in addition a great number of ships were built on the model of ours, a Roman legion was seized, some divisions of foreign troops were intercepted, Gallic merchants were assembled for a levy, considerable forces of barbarians were attracted by means of the booty from the provinces themselves, and all these were trained for naval service under the direction of those responsible for that crime.
Panegyrici Latini ‘VIII. Panegyric on Constantius Caesar’ §12 (Anon. delivered 297)


When the anonymous panegyrist says that Carausius “seized” a legion (which means, of course, that a legion defected to Carausius), in the singular, he is presumably referring to a legion stationed on the Continent. There were three legions resident in Britain, and Carausius must, surely, have had their support – it’s hard to believe that Roman sources would have missed the opportunity to mention any setbacks.
Actually, Carausius issued a series of coins commemorating nine legions, but only two of the British legions – II Augusta and XX Valeria Victrix, both stationed in Britannia Superior (the South) – were featured. The missing legion being VI Victrix, based at York, in Britannia Inferior (the North). It seems reasonable to suppose that the nine legions commemorated were those that had furnished vexillations (detachments) for Carausius’ task force in Gaul – the men who had backed his rebellion. In one case it was most (probably not all) of a legion, with its commander (the vexillations would have been lead by lower ranking officers), that had sided with Carausius, and was mentioned by the panegyrist. The most likely candidate is XXX Ulpia Victrix, whose base was at today’s Xanten, on the lower Rhine. VI Victrix was, probably, not commemorated simply because it did not serve with Carausius in Gaul. The legion does, however, feature on a recently recognized (2001), later, coin of Carausius.[*]
A silver denarius of Carausius, depicting him being welcomed by Britannia. The inscription reads:
(Come, awaited one)
with the letters RSR beneath.

Carausius probably had his capital in London, and it is fairly certain that he established a mint there. Some, though by no means all, of his coins bear a mint mark. Those bearing the letter L are considered to have been minted in Londinium (London). Some bear the letter C, but, although there are several candidates – Camulodunum (Colchester), Clausentum (Bitterne, possibly), Calleva Atrebatum (Silchester), Corinium (Cirencester), or, if the C is meant to be a G, Glevum (Gloucester) – their provenance remains unknown. Carausius would appear to have also controlled a portion of northern Gaul, stretching from the coast to, at least, Rotomagus (Rouen), where, probably only early in his reign, he is also believed to have minted coins. Inscriptions on his coinage suggest that Carausius saw himself as a saviour, restoring the traditional values of Rome’s ‘good old days’.


Other than on his coinage, the only inscription to feature Carausius is on a milestone found near Carlisle (RIB 2291). It provides the fullest version of his name:
This is interpreted as ‘Imperator Caesar Marcus Aurelius Mausaeus Carausius Pius Felix the Invincible Augustus’. In fact, MAVS does not represent a common Latin name, and, although Mausaeus is generally accepted, it is not inconceivable that there has been a mason’s error – for instance, MAES would represent the common name Maesius.
Subsequently, the milestone was inverted – the end with the dedication to Carausius being buried in the ground – and a new dedication to Constantine was inscribed on the other, now exposed, end. There had been a third inscription between these two, but it was thoroughly erased.

According to a panegyric (speech of praise) on Maximian, probably delivered on 21st April (Rome’s birthday) 289, since the suppression of the Bagaudae, Maximian had been busy dealing with German invaders:

Scarcely was that unhappy outburst [of the Bagaudae] stilled when immediately all the barbarian peoples threatened the destruction of the whole of Gaul … What god would have brought us such unhoped-for salvation had you [Maximian] not been present?
I pass over your countless battles and victories all over Gaul. For what speech could do justice to so many great exploits?
Panegyrici Latini ‘X. Panegyric on Maximian’ §§5–6 (Mamertinus)

Maximian subsequently crossed the Rhine frontier into Germany, eliciting the panegyrist Mamertinus to exclaim:

… all that I see beyond the Rhine is Roman!
Panegyrici Latini ‘X. Panegyric on Maximian’ §7

At any rate, seemingly by 288 Maximian was in a position to make preparations to cross the Channel and overthrow Carausius. Mamertinus (§12) says that, aided by good weather, Maximian, “throughout almost the whole year”, constructed warships – inland, on rivers, presumably because Carausius was in control of the Channel. It appears that Maximian had defeated Carausius’ forces in northern Gaul, and the assault on Britain was about to be launched, when Mamertinus was speaking.

It is through your good fortune, through you felicity, Emperor, that your soldiers have already reached the Ocean in victory, and that already the receding waves have swallowed up the blood of enemies slain upon that shore.
In what frame of mind is that pirate [Carausius] now, when he can see your armies on the point of penetrating that channel (which has been the only reason his death has been delayed until now) and, forgetting their ships, pursuing the receding sea where it gives way before them? What island more remote, what other Ocean, can he hope for now? By what means can he finally escape the punishment he owes the State unless he is swallowed up by the earth and devoured, or snatched away by some whirlwind onto inaccessible crags?… anyone at all may easily perceive what great success is likely to await you in this maritime venture, considering what a favourable bout of weather has already gratified you.
Panegyrici Latini ‘X. Panegyric on Maximian’ §§11–12

Great success, however, clearly didn’t await Maximian. A glancing reference in a later panegyric might suggest that the expedition was scotched by “inclemency of the sea”.[*] It is, though, quite possible that Maximian’s forces suffered a defeat at the hands of Carausius – a view which seems to be supported by Eutropius, who reports that:

With Carausius, however, as hostilities were found vain against a man eminently skilled in war, a peace was at last arranged.
Breviarium Ab Urbe Condita IX, 22

And Aurelius Victor states that:

… Carausius was allowed to retain his sovereignty over the island, after he had been judged quite competent to command and defend its inhabitants against warlike tribes.
Liber De Caesaribus §39
Bronze antoninianus of Carausius, depicting him and ‘his brothers’, which has been dated 292–3.[*]

The coin issued by Carausius pictured rightabove shows him alongside Diocletian and Maximian, with the legend CARAVSIVS ET FRATRES SVI, that is ‘Carausius and his Brothers’. On the reverse is PAX AVGGG, which represents ‘the Peace of the three Augusti’.

Carausius may have seen himself as a ‘brother’ to Diocletian and Maximian, but it seems clear that the feeling was not reciprocated. They were simply tolerating Carausius until they were in a position to remove him. In 293, Diocletian inaugurated a system of government known as ‘the tetrarchy’ (rule by four). Each Augustus elevated one of their subordinates to the rank of Caesar – Galerius in the case of Diocletian; Constantius (known as Constantius Chlorus, i.e. ‘the Pale’) in the case of Maximian – and control of the Empire was shared between the four of them. The problem of Carausius became Constantius’ responsibility. He took prompt action:

… you straightway made Gaul yours, Caesar, simply by coming here. Indeed the swiftness with which you anticipated all reports of your accession and arrival caught the forces of that band of pirates who were then so obstinate in their unhappy error, trapped within the walls of Gesoriacum [Boulogne], and denied access to the Ocean which washes the gates of the city to those who had relied for so long upon the sea. In this you displayed your divine forethought, and the outcome matched your design, for you rendered the whole bay of the port, where at fixed intervals the tide ebbs and flows, impassable to ships by driving piles at its entrance and sinking boulders there. You thereby overcame the very nature of the place with remarkable ingenuity, since the sea, moving back and forth in vain, seemed to make sport, as it were, of those to whom escape was denied, and offered as little practical help to those shut in as if it had ceased to ebb at all.…
… your divine forethought, Caesar, devised an efficacious plan and did not insult the element [i.e. the sea], so that it did not provoke its hatred but earned its respectful compliance. For what other construction are we to put upon it when immediately necessity and trust in your clemency had put an end to the siege the very first wave which bore down upon those same barriers burst through them, and that whole line of trees, unconquered by the surge as long as there was a need for it, collapsed as if a signal had been given and its guard duty was at an end? The result was that no one could doubt that the harbour, which had been closed to the pirate so he could not bring help to his men, had opened of its own accord to aid our victory. For the whole war could have been finished immediately, invincible Caesar, under the impulse of your courage and good fortune, had not the necessity of the case persuaded you that time should be spent on the building of a navy. During the whole of this period, however, you never ceased to destroy those enemies whom terra firma permitted you to approach …
Panegyrici Latini ‘VIII. Panegyric on Constantius Caesar’ §§6–7 (Anon. delivered 297)

Whilst Constantius waited until a new fleet was built, Carausius was over­thrown and killed.

At the end of seven years [i.e. in 293], Allectus, one of his supporters, put him to death, and held Britain himself for three years subsequently …[*]
Eutropius Breviarium Ab Urbe Condita IX, 22


Eutropius assigns Carausius a reign of seven years and Allectus a reign of three. However, Aurelius Victor says:
He [Carausius], in fact, was treacherously overthrown six years later by a man named Allectus …
Liber De Caesaribus §39
Victor allots Allectus a reign of “a short while”. There is no certainty, but, on balance, it seems likely that Carausius rebelled in the autumn of 286; he was overthrown by Allectus in 293 (Constantius seems to have taken Boulogne pretty quickly after his elevation to Caesar, which was on 1st March 293 – it is widely supposed that his success precipitated the downfall of Carausius); Allectus was overthrown by Constantius (as we shall see) in 296.
Victor is the only source who defines the position held by Allectus at the time he rebelled against Carausius. The Latin phraseology Victor uses, though, is open to interpretation, and, encouraged by a longstanding interpretation of the RSR inscription found on some of Carausius’ coins (as on the silver denarius pictured previously), it has been generally supposed that Victor meant that Allectus was Carausius’ finance minister. However, in 1998 Guy de la Bédoyère convincingly demonstrated that RSR is actually a literary allusion, so there is no longer a need to confine Allectus to the finance department.[*] Anthony R. Birley interprets Victor as meaning that Allectus was “in supreme charge by Carausius’ permission”, and suggests he was Carausius’ Praetorian prefect.[*] Anyway, Victor proceeds to claim that Allectus:
… fearing execution because of his misdeeds, had seized power through a criminal act.
Liber De Caesaribus §39
However, the apparently smooth transfer of power from Carausius to Allectus suggests that the latter had the troops’ backing.
Having described the first stages of Carausius’ rebellion (“this nefarious act of brigandage”, above), the anonymous author of the ‘Panegyric on Constantius Caesar’ proceeds to say:
Although your [i.e. Constantius and his ruling partners’] armies were unconquerable in courage, they were novices, however, in the art of seafaring, and we heard that an evil and massive war had grown out of that most miserable act of piracy, although we were confident about its outcome. For, in addition, long impunity for their crime had inflated the audacity of desperate men, so that they gave out that that inclemency of the sea, which had delayed your victory by some necessity of fate, was really terror inspired by themselves, and they believed, not that the war had been interrupted by deliberate policy, but that it had been abandoned out of despair, so much so that now that his fear of a common punishment had been laid to rest one of the henchmen of the archpirate killed him: he judged that after all imperial power was recompense for such a great hazard.
Panegyrici Latini ‘VIII. Panegyric on Constantius Caesar’ §12
The “inclemency of the sea” episode is generally seen as a reference to Maximian’s failed attempt to dislodge Carausius in 289 – either as a genuine reason for the loss of Maximian’s fleet, or as a cover for it being smashed by Carausius’ naval superiority.
The panegyrist stresses Britain’s importance to Rome:
… a land so abundant in crops, so rich in the number of its pastures, so overflowing with veins of ore, so lucrative in revenues, so girt with harbours, so vast in circumference.
Panegyrici Latini ‘VIII. Panegyric on Constantius Caesar’ §11
Britain would play a crucial role supplying grain to the Rhine garrisons[*].
The Roman walls of Portchester Castle, identified as, the Saxon Shore fort, Portus Adurni.

Exactly when in the late-3rd century, and by whom, the decision to establish a coastal defence system in the south-east of Britain – comprising the, so-called, ‘Saxon Shore’ forts – was taken is difficult to determine (a popular theory is that Probus, 276–282, was responsible). What is clear, from numismatic evidence, however, is that, even if it was not initiated by Carausius, both he and Allectus developed the system. The forts get their name from an entry in the Notitia Dignitatum, listing nine forts, identified with sites between the Wash and the Solent, that were under the command of the comes litoris Saxonici (count of the Saxon Shore) about a century after the time of Carausius and Allectus. Perhaps the term ‘Saxon Shore’ was applied because this stretch of coast was vulnerable to raids by the Saxons, but it may be that the Saxons referred to were settlers rather than raiders – by 297, the practice of settling barbarians on land inside the Empire, to provide a ready supply of troops to fight against barbarians outside the Empire, was already established.[*] Whatever the origin of the name, it is, for the most part, accepted that the purpose of this group of forts was to combat sea-borne, Germanic, raiding parties (and presumably, for Carausius and Allectus, an invading Roman force).


At most of the nine forts insufficient evidence has been found to pinpoint their building dates. Coin histograms and building-style can give a general idea of when a particular fort was constructed.
The Saxon Shore Forts named in the Notitia Dignitatum are usually identified with the sites shown here.
The Saxon Shore Forts named in the
Notitia Dignitatum are usually identified
with the sites shown above.
Brancaster and Reculver, which have the traditional ‘playing card’ shape and an absence of bastions, are evidently the earliest – built in the first half of the 3rd century, and subsequently incorporated into the system. The rest of the forts clearly date from the late-3rd century, though they are not built to a standard pattern.[*] Two of them have been closely dated. Portchester, by virtue of a coin of Carausius found in the construction levels, must be later than 286, and may well have been built under Carausius; and Pevensey, where timber piles and coins indicate that the fort was built under Allectus (293–296).
Not included by the Notitia is the fort at Caister-on-SeaCaister-on-Sea, Norfolk – a ‘playing card’ fort, apparently built in the early-3rd century and occupied until the late-4th. Walton CastleWalton Castle, Suffolk, is also missing from the Notitia. Actually, this fort is now missing, full stop, having been lost to coastal erosion. What is known of it, though, suggests it was built in late-3rd century style. At BitterneBitterne, an eastern suburb of Southampton, defences, apparently of the late-3rd century, have also been found, and some writers include the site as part of the Saxon Shore fort system, but it has not been conclusively demonstrated that it was a fort – it may have been a small fortified town.

In 296, whilst Maximian guarded the Rhine frontier,[*] Constantius mounted his assault on Britain. Despite adverse weather conditions, Constantius set sail from Boulogne with a section of his army, whilst the remainder, under his Praetorian prefect Asclepiodotus, sailed from the mouth of the river Seine.[*] Aurelius Victor (Liber De Caesaribus §39) says that Asclepiodotus “was sent ahead with a detachment of the fleet and of the legions”, whereas according to the ‘Panegyric on Constantius Caesar’ (§14), which is of course the contemporary source, it was Constantius who sailed first. Either way, it was Asclepiodotus’ fleet that arrived off the coast of Britain first.[*] Allectus apparently knew of Constantius’ plan, since he had stationed a fleet near the Isle of Wight in order to intercept this section of the invading army. As luck would have it, fog enabled Asclepiodotus to slip, unnoticed, past the enemy fleet. Having landed on the British coast, Asclepiodotus’ men burned their own ships. Meanwhile, Allectus himself was evidently lying in wait, with a fleet, at another location – presumably one of the Saxon Shore Forts on the Channel coast, east of the Isle of Wight, opposite Boulogne. Constantius had still not arrived, so, leaving his fleet in place, Allectus hastily marched against Asclepiodotus.

Why did the standard-bearer himself of that criminal faction [i.e. Allectus] retreat from the shore that he held? Why did he desert his fleet and harbour, unless it was because he feared you, invincible Caesar, whose approaching sails he had seen, about to arrive at any moment? Whatever the case, he preferred to make trial of your generals than to receive in person the thunderbolt of Your Majesty – madman he, who did not know that wherever he might flee, the power of your divinity would be everywhere that your images, everywhere that your statues, are revered.
He, however, in fleeing you, fell into the hands of your men: vanquished by you, he was crushed by your armies. At last, afraid when he looked back and saw you on his heels, he was stricken out of his senses and rushed to his death so hurriedly that he did not draw up battle line or deploy all the forces which he was dragging behind him, but without a thought for his vast preparations rushed forward with those old chiefs of the conspiracy and divisions of barbarian mercenaries. And furthermore, Caesar, such an asset to the State was your good fortune that almost no Roman died in this victory of the Roman Empire. For, as I hear, none but the scattered corpses of our foulest enemies covered all those fields and hills.
Panegyrici Latini ‘VIII. Panegyric on Constantius Caesar’ §§15–16

One of the “scattered corpses” was Allectus.

Of his own accord he had discarded the apparel which he had profaned when alive, and he was discovered on the evidence of scarcely a single garment. When death was near, so truly did he foretell what was in store for him that he did not wish his body to be recognized.
Panegyrici Latini ‘VIII. Panegyric on Constantius Caesar’ §16

Those of Allectus’ Frankish mercenaries who had not been killed in the battle made for London. It would appear that Constantius was still at sea, but some ships that had become separated from his fleet in the fog now arrived in London.[*] Constantius’ soldiers:

… slaughtered indiscriminately all over the city whatever part of that multitude of barbarian hirelings had survived the battle, when they were contemplating taking flight after plundering the city. Your men not only gave safety to your provincials by the slaughter of the enemy, but also the pleasure of the spectacle.  O manifold victory of innum­erable triumphs, by which the Britains have been recovered, the might of the Franks utterly destroyed, the necessity of submission imposed besides upon the many peoples detected in that criminal conspiracy, by which, finally, the seas were swept clean and restored to everlasting peace! Well may you boast, then, invincible Caesar, that you have discovered another world, you who in restoring naval glory to Roman power have added to the Empire an element greater than all lands.
Panegyrici Latini ‘VIII. Panegyric on Constantius Caesar’ §17

It was only after the fighting was over that Constantius himself finally arrived on the scene.

A gold medallion, struck (in Gaul, at Trier – mintmark PTR) to commemorate Constantius’ British victory.
Whilst troops arrive by ship, a mounted Constantius,
(Restorer of the Eternal Light),
is welcomed by the personification of London, kneeling before her city gates.[*]
And so it was fitting that, as soon as you stepped onto that shore, a long-desired avenger and liberator, a triumphal crowd poured forth to meet Your Majesty, and Britons exultant with joy came forward with their wives and children, venerating not you alone, whom they gazed at as one who had descended from heaven, but even the sails and oars of that ship which had conveyed your divinity, and prepared to feel your weight upon their prostrate bodies as you disembarked. Nor is it any wonder if they were carried away by such joy after so many years of miserable captivity; after the violation of their wives, after the shameful enslavement of their children, they were free at last, at last Romans, at last restored to life by the true light of empire.…
… of other areas, some remain which you can acquire if you should wish, or reasons of state require: but beyond the Ocean what was there except Britain? This you have so fully recovered that those peoples, too, who cling to the extremities of the same island, obey your very nod. No reason remains for advancing, unless one were to seek the boundaries of the Ocean itself, which Nature forbids.
Panegyrici Latini ‘VIII. Panegyric on Constantius Caesar’ §§19–20

Amongst the political, military and economic reforms instigated by Diocletian was the reorganisation of regional government. Provinces were to be reduced in size and increased in number – the military and civil aspects of their administration would be separated.[*] The provinces were to be grouped into territories called dioceses – each diocese would be supervised by an official called a vicarius (from which ‘vicar’). The whole empire was to comprise twelve dioceses – one of them would be Britain. These dramatic changes, which would take a considerable time to work through, began around the time that the tetrarchy was created in 293. In 296, after the overthrow of Allectus, the new order could be introduced in Britain also.

During the reign of Caracalla (211–217), the single province of Britannia had been divided into two provinces: Britannia Superior (based on London) and Britannia Inferior (based on York).[*] Under Diocletian’s reformed system, the diocese of the Britains (dioecesis Britanniarum) comprised four provinces: Britannia Prima (based on Cirencester), Britannia Secunda (based on York), Flavia Caesariensis (based on Lincoln), and Maxima Caesariensis (based on London).


It is clear that there was more than one province of Roman Britain at the time of Constantius’ victory – the ‘Panegyric on Constantius Caesar’ refers (§17) to “the Britains” being recovered, and (§20) to “those provinces” having an abundance of craftsmen. Presumably these were still the two provinces created at the time of Caracalla. At any rate, the post-Diocletian British provinces are named in the Verona List – a document listing all the dioceses and their provinces, dating from about 314.
It is supposed that, by analogy with what happened elsewhere, Britannia Prima was formed in Britannia Superior, and Britannia Secunda in Britannia Inferior. Inscriptions on a rectangular column-base from Cirencester (Corinium) suggest that the town was capital of Britannia Prima.[*] Bishops from, what are thought to be, the capitals of the other three provinces: London (Londinium), York (Eboracum) and Lincoln (Lindum), are listed as being present at the Council of Arles in 314.[*] Flavia Caesariensis would seem to have been named after Constantius (Flavius Constantius Caesar), but, surely, Maxima Caesariensis cannot have been named after, the western Augustus, Maximian, and it would, perhaps, be peculiar if it had been named after, the eastern Caesar, Galerius Maximianus. Perhaps Diocletian’s reforms initially created just one extra British province, called Caesariensis – named after its capital, Caesarea. The problem is that there is no known Caesarea in Britain. It is possible, however, that Constantius granted London the title after he liberated the city. (London was certainly titled Augusta late in the 4th century – possibly it changed from Caesarea when Constantius became Augustus in 305.) So, this hypothetical province of Caesariensis was soon (before 305) divided to produce Maxima Caesariensis and Flavia Caesariensis – the two parts named after the western Augustus and Caesar. On the other hand, Maxima Caesariensis might be so called simply because it was the biggest or most important British province. In the Notitia Dignitatum, the governor of Maxima Caesariensis is of higher rank (consularis) than the governors of the other three provinces (praeses). This strongly suggests that London, the most important city in Britain, was the capital of Maxima Caesariensis. (The vicarius of the British provinces probably had his headquarters in London.) By default, then, Lincoln is the capital of Flavia Caesariensis and York of Britannia Secunda.
The Praetorian prefect was an emperor’s right-hand man, and, as such, wielded authority in all areas of government. The position had developed from commander of, the traditional imperial bodyguard, the Praetorian Guard. Under Constantine, however, military responsibilities were removed from the Praetorian prefect. (The Guard itself was reduced by Diocletian, then disbanded by Constantine in 312.) In the fullness of time, as recorded in the Notitia Dignitatum (c.400), there were four regional Praetorian prefectures – each prefect overseeing the dioceses that comprised a geographical area of the Empire – from west to east: the prefecture of the Gauls, the prefecture of Italy, the prefecture of Illyricum, and the prefecture of Oriens. The prefecture of the Gauls included Britain (also Spain), and was administered from Trier (in modern Germany).
An Instructive Example of Godliness ►
See recap.
In modern Belgium.
A grouping of Germanic tribes along the lower Rhine.
In particular, a Germanic people occupying territory adjoining the North Sea coast between the Elbe and Weser. Roman sources, however, clearly use the name in a general way. Eutropius’ “Saxons” could just as well come from Friesland, to the west of the Saxon heartland, or the Jutland Peninsula, to the north. Incidentally, Eutropius’ mention here is the first certain literary reference to the Saxons.
I Minervia based in  Germania Inferior
II Augusta Britannia Superior
II Parthica Italy
IV Flavia Moesia Superior
VII Claudia Moesia Superior
VIII Augusta Germania Superior
XX Valeria Victrix Britannia Superior
XXII Primigenia Germania Superior
XXX Ulpia Victrix Germania Inferior
The letters RSR, found on some of Carausius’ coins, have posed something of a conundrum. They do not seem to represent any town in Britain or northern Gaul, where the coin could have been minted. Similarly, the mysterious caption I.N.P.C.D.A features on the reverse of a unique bronze medallion. The legend Expectate veni is believed to be an allusion to a line from Virgil’s Aeneid: “From what shores do you come Hector, the long-awaited one?”  Guy de la Bédoyère* has deduced that RSR and I.N.P.C.D.A also allude to Virgil: Redeunt Saturnia Regna, Iam Nova Progenies Caelo Demittitur Alto (Eclogues IV), that is “The Saturnian kingdoms return [or “The Golden Age returns”], now a new generation is let [or “sent”] down from heaven above”.
* ‘Carausius and the Marks RSR and I.N.P.C.D.A.’, The Numismatic Chronicle Vol. 158 (1998), available online.
The Panegyrici Latini is a compendium of twelve Latin panegyrics, which, with the exception of the first (dated 100), were composed during the period 289 to 389. None of the surviving manuscripts is earlier than the 15th century. Some manuscripts, including the one considered to be most faithful to the original, attribute panegyrics X and XI to one Mamertinus. This attribution is, however, not accepted in all quarters.
Panegyrici Latini ‘VIII. Panegyric on Constantius Caesar’ §12 (Anonymous, delivered 297).
Notitia Dignitatum (Register of Dignitaries): A list of Roman civil and military posts, compiled round-about 400 (its precise date and purpose are subjects of much debate). No surviving manuscript, however, is earlier than the 15th century. All extant copies are believed to derive from a single c.10th century copy, which was apparently lost in the late-16th century.
The nine forts depicted in a copy of the Notitia Dignitatum made in 1436 (Oxford, Bodleian Library MS Canon. Misc. 378).
A bar-chart displaying the number of coins found from successive time periods. The theory is that the number of coins of a particular period that were lost at a site, is related to the intensity of occupation of the site during that period.
In effect, deputy emperor and designated heir.
The speech was delivered, in the presence of Constantius, in the spring – apparently shortly after the anniversary of his accession (1st March) – of 297 (the year is now well established).
In his paper of 1998 (‘Carausius and the Marks RSR and I.N.P.C.D.A.’, The Numismatic Chronicle Vol. 158, available online), Guy de la Bédoyère writes:
It [RSR] is normally interpreted as Rationalis Summae Rei, ‘financial minister’. This is an attested Roman position, though not in Britain, and accords with the description by Aurelius Victor of Allectus as a high official under Carausius: Allectus … Qui cum eius permissu summae rei praeesset, “Allectus … who by his [Carausius’] leave had been placed in charge of the ‘financial department’”.… However, in addition to the fact that Victor does not use the full title to describe Allectus, there are two further problems with this expansion of RSR. Firstly, the normal abbreviated epigraphic form of the Rationalis Summae Rei office is RAT.S.R. Secondly, and more importantly, it does not appear on any other Roman coins at any other time.
And in a footnote:
Summa res here [i.e. in Victor] is believed to be the financial office, but in the absence of the qualifying rationalis from the text it must be stressed that the phrase has a wide range of possible meanings; for example, Cicero, de Re Publica I.xxvi.42, summa rerum, ‘supreme authority’.
Guy de la Bédoyère convincingly shows that RSR is, in fact, an allusion to Virgil’s phrase (Eclogues IV): Redeunt Saturnia Regna, “The Saturnian kingdoms return”, i.e. “The Golden Age returns”.
Anthony R. Birley The Roman Government of Britain (2005) III, 2.
Excavations on the site of an unfinished monumental complex, south of St Paul’s Cathedral in London, produced timber remains dating from 294. It is thought possible that this would have been the palace of Allectus, but he never survived to complete it.
Though not built to a standardized design, all the forts, bar Brancaster and Reculver, share the features – such as the bastions (presumably used for mounting artillery pieces) and high, thick walls seen in the photograph of Portchester – typical of late-Roman military architecture. An evolution of the architecture is evident – Burgh Castle representing a transitional stage between the traditional and late types, and Pevensey being the most modern.
The panegyrist does not, in fact, mention Asclepiodotus at all – the glory belongs to Constantius. The abbreviated histories of Aurelius Victor and Eutropius, however, unequivocally attribute the campaign’s success to, Constantius’ Praetorian prefect, Asclepiodotus. The only other detail they provide is Victor’s assertion that Asclepiodotus “was sent ahead” – but Victor could have simply assumed that, since he arrived first, Asclepiodotus had set off first. The panegyrist, although he was intent on magnifying Constantius’ achievement, could hardly tamper with facts that would have been well known to his audience, so assuming that the panegyrist is correct, it is something of a mystery why Constantius’ crossing took so long. A later panegyric* might provide a clue. It says that Constantius “sailed over such a calm sea”, whilst, according to our contemporary panegyric (§14), the ocean “was raging”. Could it be, then, that stormy weather caused Constantius to turn back, regroup his fleet and wait for the storm to blow over before finally crossing to Britain?
* Panegyrici Latini ‘VI. Panegyric on Constantine’ (anonymous) §5, delivered 310.
See The Roman Army in Britain, Part II.
See The Caledonian Campaigns of Septimius Severus.
The inscriptions (RIB 103) are on three faces of the column-base (probable letters are underdotted, restored letters are in square brackets, | indicates a line break).
To Jupiter Best and Greatest, Lucius Septimius …, the Most Perfect, governor (praeses) of Britannia Prima, restored this, a citizen of the Remi.
This statue and column was raised under the ancient religion.
Left side:
Septimius restores this, Prima province’s ruler.
The Remi were a tribe from north-eastern Gaul. The city of Reims is named from them.
The Acta Concilii Arelatensis names three bishops attending from Britain. That Eborius was bishop of York (Eborius episcopus de civitate Eboracensi), and Restitutus was bishop of London (Restitutus episcopus de civitate Londiniensi) is clear. Adelphius, though, is episcopus de civitate colonia Londiniensium. It is generally accepted that colonia Londiniensium should be emended to colonia Lindiniensium, meaning Lincoln – which was established as a colonia (colony) around the year 90. Also attending the Council from Britain were Sacerdos, a priest, and Arminius, a deacon. Presumably(?) these two were representing the absent bishop of the fourth province, whose see is not named.
Ammianus Marcellinus:
… the old town of Lundinium, which later times called Augusta.
Res Gestae XXVII, 8
… Augusta, which was earlier called Lundinium …
Res Gestae XXVIII, 3
The ‘Panegyric on Constantius Caesar’ mentions (C§9 & §21) that captured Germanic barbarians (specifically named are the Chamavi, Frisii and Franks) were allocated land to cultivate in areas of Gaul that had become depopulated. In return, the settled tribesmen had an ongoing obligation to serve in the Roman military when required. These Germanic farmer/soldiers are called laeti (the earliest use of the term appears in §21 of the panegyric). It is not beyond the bounds of possibility that Carausius and Allectus could have settled Germanic people on the Saxon Shore.
The Notitia Dignitatum notes that two forts in Gaul were “on the Saxon Shore”. Both sites are unidentified (there are, of course, theories), but one, Grannona, is under the command of the dux tractus Armoricani et Nervicani (duke of the Armorican and Nervian regions) and the other, Marcis, under the dux Belgicae secundae (duke of Belgica Secunda). These two commands cover the northern coast of Gaul – the coast which Eutropius had associated with Saxon raids in 285. There is, however, no conclusive evidence that Saxons had actually settled on the Saxon Shore, on either side of the Channel, by around 400, when the Notitia Dignitatum was compiled.
Some scholars prefer to see Roman town walls as the equivalent of the great Victorian town halls of Northern England, that is to say, as impressive monuments demonstrating civic pride, rather than defences built in response to a particular threat. See Simon Esmonde Cleary ‘Urban Fortification in Roman Britain: Military Defence or Civic Monument?’, freely available online – this paper was published in Spanish, as ‘Fortificación en la Britannia Romana: ¿defensa militar o monumento cívico?’, Murallas de Ciudades en el Occidente del Impero Romano: Lucus Augusti como Paradigma (2007).
For you yourself lord Maximian, Emperor eternal … protected that whole frontier not with equestrian forces, not with foot soldiers, but by the terror inspired by your presence: Maximian on the bank was worth as many armies as you like!
Panegyrici Latini ‘VIII. Panegyric on Constantius Caesar’ §13
Malcolm Lyne ‘Two Notes on the Coinage of Carausius’, The Numismatic Chronicle Vol. 161 (2001), available online.
On the coin’s reverse, set around the lower body of Peace, are the letters SCP.   R.A.G. Carson* argues that this configuration of letters means that the coin was one of the latest issues of Carausius produced by the ‘C’ mint, and should be dated 292–3. This date seems to be generally accepted.
* ‘The Sequence-marks on the Coinage of Carausius and Allectus’, Mints, Dies and Currency: Essays dedicated to the memory of Albert Baldwin (1971).
See here.
overlaid on map
This unique medallion, known as the Arras Medallion, was found in a hoard at Beaurains, near Arras, in 1922. In fact, the picture is of a copy, made in 1927, in the British Museum. It has not been possible to establish beyond doubt the current whereabouts of the original.
The text of the panegyric (§17) doesn’t make it clear, but presumably the ships that lost their bearings in the fog were from Constantius’ fleet. Asclepiodotus crossed from the Seine and landed near the Isle of Wight – any ships of his would have been extraordinarily lost to accidentally end up in London.
Inscriptiones Latinae Selectae
Roman Inscriptions of Britain online.