Historia Brittonum, states that Aelle was the son of Iffi, the grandson of Giulgis, the great-grandson of Sguerthing and the great-great-grandson of Soemil, who first separated Deira from Bernicia, however since Bernicia did not exist at that time, it is assumed that the document, refered to the former British Kingdom of Bryneich
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559AD. At the death of Ida, Aelle made his first moves to become the king of Deira
560AD. After the death of Ida of Bernicia the year before, Aelle who was probably one of his underlords, seized the Bernician lands below the river Tees and decared himself king..
580AD.The army of Peredyr and Gwrgi of the british kingdom of Ebrauc marched north to fight the Angles of the north. They were both slain when they came against the forces of (king Adda?) at Caer Greu. It was more likely to have been the forces of king Aelle they met, since Adda had been dead for many years by then. Eubrauc was based around York and any army raised there would have been at threat to Deira. In fact the Deirians rose up under Aelle, moved on the city of Ebrauc and King Peredyr’s son was forced to flee the kingdom.
One of Aelle’s sons was Edwin who became king of Northumbria and his daughter married Æthelfrith of Bernica.
