The Kingdom of Sussex, (Suth Seaxe, i.e. the South Saxons), is one of the kingdoms of Anglo-Saxon Britain, the boundaries of which coincided in general with those of the modern county of Sussex. A large part of that district, however, was covered in early times by the forest called Andred.
According to the traditional account given in the Anglo-Saxon Chronicle, it was in 477 that a certain Ella (AElle) led the invaders ashore at a place called Cymenes ora and defeated the inhabitants. A further battle at a place called Mearcredes burne is recorded under the year 485, and in the annal for 491 we read that Ella and Cissa his son sacked Anderida and slew all the inhabitants. Ella is the first king of the invading race whom Bede describes as exercising supremacy over his fellows, and we may probably regard him as an historical person, though little weight can be attached to the dates given by the Chronicle.
The history of Sussex now becomes a blank until 607, in which year Ceolwulf of Wessex is found fighting against the South Saxons. In 681 Wilfrid of York, on his expulsion from Northumbria by Ecgfrith, retired into Sussex, where he remained until 686 converting its pagan inhabitants. According to Bede, AEthelwald, king of Sussex, had been previously baptized in Mercia at the suggestion of Wulfhere, who presented him with the Isle of Wight and the district about the Meon. After Wilfrid's exertions in relieving a famine which occurred in Sussex the king granted to him eighty-seven hides in and near the peninsula of Selsey which, with a lapse until 709 after Wilfrid's retirement, remained the seat of the South Saxon bishopric until the Norman Conquest.
Shortly afterwards, however, AEthelwald was slain and his kingdom ravaged by the exiled West Saxon prince Ceadwalla. The latter was eventually expelled by two princes named Berhthun and Andhun, who thereupon assumed the government of the kingdom. In 686 the South Saxons attacked Hlothhere, king of Kent, in support of his nephew Eadric, but soon afterwards Berhthun was killed and the kingdom subjugated for a time by Ceadwalla, who had now become king of Wessex.
Of the later South Saxon kings we have little knowledge except from occasional charters. In 692 a grant is made by a king called Nothelm to his sister, which is witnessed by two other kings called Nunna and Uuattus. Nunna is probably to be identified with Nun, described in the Chronicle as the kinsman of Ine of Wessex who fought with him against Geraint of Dumnonia, king of the West Welsh, in 710. According to Bede, Sussex was subject to Ine for a number of years.
A grant, dated by Birch about 725, is made by Nunna to Eadberht, bishop of Selsey, and to this too Uuattus appears as a witness. In 722 we find Ine of Wessex at war with the South Saxons, apparently because they were supporting a certain Aldbryht, probably an exile from Wessex. An undated grant is made by Nunna about this time, which is witnessed by a King AEthelberht.
After this we hear nothing more until shortly before 765, when a grant of land is made by a king named Aldwulf with two other kings, Aelfwald and Oslac, as witnesses. In 765 and 770 grants are made by a King Osmund, the latter of which is witnessed by Offa of Mercia. Offa also appears as witness to two charters of an AEthelberht, king of the South Saxons, and in 772 he grants land himself in Sussex, with Oswald, dux of the South Saxons, as a witness. It is probable that about this time Offa definitely annexed the kingdom of Sussex, as several persons, Osmund, AElfwald and Oslac, who had previously used the royal title, now sign with that of dux.
In 825 the South Saxons submitted to Ecgberht, and from this time they remained subject to the West Saxon dynasty. The earldom of Sussex seems later to have been held sometimes with that of Kent.
Based on a 1911 encyclopedia article.