FROM DOT TO DOMESDAY   Early Medieval   The Birth of Nations: England
SUSSEX
Sussex, the Kingdom of the South-Saxons, approximated to the area of the modern counties of East and West Sussex. The history of Sussex is dimly recorded, only two of its kings being anything more than just names. By the end of the 8th century the South-Saxons appear to have become a Mercian province. Following Mercia's decisive defeat by Wessex, in 825, Sussex submitted to, and was eventually absorbed by, Wessex.
King of the South-Saxons
477 - 514  Ælle
Alongside the year 477, the 'Anglo-Saxon Chronicle' notes the arrival of Ælle, with his sons: Cymen, Wlenking, and Cissa "... in three ships; landing at a place that is called Cymenshore. There they slew many of the Welsh [Britons]; and some in flight they drove into the wood that is called Andred'sley."  An entry for 485 reports Ælle in battle against the Britons "... nigh Mecred's-Burnsted."  Presumably Ælle was the victor, although there is no mention. In 490, however, there is no disputing the outcome when he "... and Cissa besieged the city of Andred [Roman Anderida, now Pevensey], and slew all that were therein; nor was one Briton left there afterwards."  Ælle's authority was not just local. He is described by Bede as the first "... of the English kings who ruled over all the southern provinces that are divided from the northern by the river Humber and the borders contiguous to it ..."  Taking its cue from Bede, the 'Anglo-Saxon Chronicle' lists Ælle as the first Bretwalda.
Sir Frank Stenton ('Anglo-Saxon England') writes: "There is no means of checking the dates in the Chronicle. But the tradition which placed Ælle in the last quarter of the fifth century agrees with Gildas' description of Britain in the years before the battle of Mons Badonicus, and the long interval between his overlordship and that of Ceawlin strengthens the impression given by Procopius that the English advance against the Britons was suspended for at least a generation after that battle."  See: Dark Ages
Henry of Huntingdon (d.c.1155), in his somewhat florid 'Historia Anglorum' (History of England), writes: "About this time [514] died Ælla [Ælle], King of the South-Saxons, who enjoyed all the prerogatives of English royalty, having under him kings and nobles and governors. His son Cissa succeeded him, and their posterity afterwards. But in process of time, their power was much diminished, and at length they were brought under subjection by other kings."
 
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514 - 590  Cissa
Roger of Wendover notes that when Ælle died, in 514, he "... was succeeded by his son Cissa, from whom Chichester, which he founded, received its name."  Roger claims that Cissa was king of Sussex in 586, and that: "In the year of grace 590, on the death of Cissa, king of the South-Saxons, that kingdom devolved on Ceaulin [Ceawlin], king of the West-Saxons."  Clearly, a reign of seventy-six years is not credible.
Under the date 607, the 'Anglo-Saxon Chronicle' simply states: "This year Ceolwulf fought with the South-Saxons."
before 675 - 685  Æthelwalh
In 681, Bede reports that St.Wilfrid (who had been Bishop of York but was now an exile, having been expelled by King Ecgfrith of Northumbria) arrived in Sussex "... which extends from Kent to the south and west, as far as the West Saxons, containing land of 7,000 families, and was at that time still in bondage to pagan rites, he administered to them the Word of faith, and the Baptism of salvation. Ethelwalch [Æthelwalh], king of that nation, had been, not long before, baptized in the province of the Mercians, at the instance of King Wulfhere, who was present, and received him as his godson when he came forth from the font, and in token of this adoption gave him two provinces, to wit, the Isle of Wight, and the province of the Meanware, in the country of the West Saxons....
The Meanware were the inhabitants of the Meon valley - in what is now Hampshire, opposite the Isle of Wight.
.... The bishop, therefore, with the king's consent, or rather to his great joy, cleansed in the sacred font the foremost ealdormen and thegns of that country; and the priests, Eappa and Padda, and Burghelm, and Oiddi, either then, or afterwards, baptized the rest of the people. The queen, whose name was Eabae, had been baptized in her own country, the province of the Hwiccas [Hwicce]. She was the daughter of Eanfrid, the brother of Aenhere, who were both Christians, as were their people ...
The Mercian sub-kingdom of the Hwicce roughly equates to modern Worcestershire, Gloucestershire and western Warwickshire.
... Bishop Wilfrid, while preaching the Gospel to the people, not only delivered them from the misery of eternal damnation, but also from a terrible calamity of temporal death. For no rain had fallen in that district for three years before his arrival in the province, whereupon a grievous famine fell upon the people and pitilessly destroyed them; insomuch that it is said that often forty or fifty men, wasted with hunger, would go together to some precipice, or to the sea-shore, and there, hand in hand, in piteous wise cast them themselves down either to perish by the fall, or be swallowed up by the waves. But on the very day on which the nation received the Baptism of the faith, there fell a soft but plentiful rain; the earth revived, the fields grew green again, and the season was pleasant and fruitful. Thus the old superstition was cast away, and idolatry renounced, the heart and flesh of all rejoiced in the living God, for they perceived that He Who is the true God had enriched them by His heavenly grace with both inward and outward blessings... At this time, King Ethelwalch gave to the most reverend prelate, Wilfrid, land to the extent of eighty-seven families, to maintain his company who were wandering in exile. The place is called Selaeseu, [Selsey] that is, the Island of the Sea-Calf; it is encompassed by the sea on all sides, except the west, where is an entrance about the cast of a sling in width; which sort of place is by the Latins called a peninsula, by the Greeks, a cherronesos. Bishop Wilfrid, having this place given him, founded therein a monastery, chiefly of the brethren he had brought with him, and established a rule of life; and his successors are known to be there to this day. He himself, both in word and deed performed the duties of a bishop in those parts during the space of five years, until the death of King Egfrid [Ecgfrith], and was justly honoured by all. And forasmuch as the king, together with the said place, gave him all the goods that were therein, with the lands and men, he instructed all the people in the faith of Christ, and cleansed them in the water of Baptism. Among whom were two hundred and fifty bondsmen and bondswomen, all of whom he saved by Baptism from slavery to the Devil, and in like manner, by giving them their liberty, set them free from slavery to man."
Bede had earlier explained that St.Wilfrid's was not the only, or indeed first, monastic institution in Sussex: "... there was among them a certain monk of the Scottish nation, whose name was Dicul, who had a very small monastery, at the place called Bosanhamm, [Bosham] encompassed by woods and seas, and in it there were five or six brothers, who served the Lord in humility and poverty; but none of the natives cared either to follow their course of life, or hear their preaching."
In February 685, the South Saxons helped Eadric of Kent overthrow his uncle, Hlothere. Later in the same year, however, Sussex's fortunes took a dramatic change. Cædwalla "... a young man of great vigour, of the royal race of the Gewissæ [Wessex], an exile from his country, came with an army, slew Ethelwalch [Æthelwalh], and wasted that province with cruel slaughter and devastation; but he was soon expelled by Berthun and Andhun, the king's ealdormen, who held in succession the government of the province."  But that wasn't to be the end of the matter. Cædwalla soon took the throne of Wessex, and, quickly returning to Sussex, he killed Berthun "... and the province was reduced to more grievous slavery: Ini [Ine], likewise, who reigned after Cædwalla, oppressed that country with the like servitude for many years; for which reason, during all that time, they could have no bishop of their own; but their first bishop, Wilfrid, having been recalled home, they were subject to the bishop of the Gewissæ, that is, the West Saxons, who were in the city of Venta [Winchester]."
After the brief period of relative illumination provided by Bede, the history of Sussex, once more, fades into almost complete obscurity. The few surviving charters show that Sussex was divided amongst a number of kings. The name of King Nunna (also called Nothhelm) is found associated with a king called Watt (692), and a king and queen called Æthelstan and Æthelthryth (714). The 'Anglo-Saxon Chronicle' refers to Nunna as a "relative" of Ine, king of Wessex, when it reports that, in 710, they were fighting against the "Welsh" (i.e. the Britons of Dumnonia), under their king, Geraint.
The British Kingdom of Dumnonia comprised Cornwall, Devon, and possibly parts of Dorset and Somerset.
Ine is noted fighting against the South-Saxons in 722. They had given refuge to one Ealdberht, whom Ine had exiled. Ine fought against them again, in 725, this time killing Ealdberht.  By 765, charters suggest that at least two of the kings of Sussex had become subject to Offa of Mercia. Symeon of Durham records that, in 771, Offa "... subdued by arms the people of the Hestingi [men of Hastings]."  A South-Saxon king ('rex' in Latin) called Osmund appears in a charter of 770, but in 772 he is styled 'dux' (i.e. ealdorman). There is, therefore, a reasonable likelihood that, by 772, Offa had annexed Sussex. (Similarly, one Aldulf, previously styled 'rex' appears later as 'dux').
Following the defeat of Beornwulf of Mercia, by Ecgberht of Wessex, in 825, and the subsequent expulsion of the incumbent ruler of Kent, one Baldred, by Ecgberht's son, Æthelwulf; Kent, Sussex, Essex (and also Surrey) surrendered to Wessex. These provinces formed a sub-kingdom of Wessex, and then, in 860, were integrated into Wessex proper.
Translations:
Roger of Wendover 'Flores Historiarum' by J.A. Giles
Symeon of Durham 'Historia Regum' by J. Stevenson
'Anglo-Saxon Chronicle' by Rev. James Ingram/Dr. J.A. Giles
Henry of Huntingdon 'Historia Anglorum' by Thomas Forester
Bede 'Historia Ecclesiastica Gentis Anglorum' by J.A. Giles, revised by A.M. Sellar