When we turn to the British Islands we find, as we should expect, no traces of the Druids in England and Wales after the conquest of Anglesea mentioned above, except in the story of Vortigern as recounted by Nennius.
Among other matters reference is made to the introduction of Christianity in the reign of Tiberius; the persecution under Diocletian; the spread of the Arian heresy; the election of Maximus as emperor by the legions in Britain, and his subsequent death at Aquileia; the incursions of the Picts and Scots into the southern part of the island; the temporary assistance rendered to the harassed Britons by the Romans; the final abandonment of the island by the latter; the coming of the Saxons and their reception by Guortigern (Vortigern); and, finally, the conflicts between the Britons, led by a noble Roman, Ambrosius Aurelianus, and the new invaders.
Vortigern is said to have granted Hengest as much land as an ox-hide could encompass, and the hide being cut into strips the site of Tong Castle was accordingly marked out.
Tradition also asserts, according to the 12th century chronicler, Geoffrey of Monmouth, that it was in Tong Castle that Vortigern met Rowena, Hengest's daughter, and became so enamoured of her as to resign his kingdom to her father In the time of Richard II.
They were apparently called in by the British king Vortigern (q.v.)to defend him against the Picts.
In 455 the Saxon Chronicle records a battle between Hengest and Horsa and Vortigern at a place called Aegaels threp, in which Horsa was slain.
The story of Vortigern and Rowena takes its final form in the Historia Britonum; and Merlin makes his first appearance in the prelude to the Arthur legend.
VORTIGERN (GUORTHIGIRNUS, WYRTGEORN), king of the Britons at the time of the arrival of the Saxons under Hengest and Horsa.
It seems clear, however, that Vortigern made use of them to protect his kingdom against the Picts and Scots, and rewarded them for their services with a grant of land.
The Historia Brittonum is our only authority for the marriage of Vortigern with the daughter of Hengest before the war.
There are signs of the existence of two parties in the national opposition to the invaders, but as Pascent, son of Vortigern, is said by Nennius to have held his dominions in the west by leave of Ambrosius, the Roman element seems to have triumphed.