In 616, Æthelfrith was succeeded by Edwin of Northumbria, a Deiran. Edwin banished Æthelfrith's sons, including both Oswald and Oswiu of Northumbria. Both spent their exile in Dál Riata, a kingdom spanning parts of northeastern Ireland and western Scotland. Oswiu was a child when he came to Dál Riata, and grew up in an Irish milieu. He became a fluent speaker of Old Irish, and may have married a princess of the Uí Néill dynasty, probably Fín the daughter (or possibly granddaughter) of Colmán Rímid. Aldfrith was a child of this marriage, but his date of birth is unrecorded. He was probably thus a cousin or nephew of the noted scholar Cenn Fáelad mac Aillila, and perhaps a nephew of Bishop Finan of Lindisfarne. Irish law made Fín's kin, the Cenél nEógain of the northern Uí Néill, responsible for his upbringing. The relationship between Aldfrith's father and mother was not considered a lawful marriage by Northumbrian churchmen of his day, and he is described as the son of a concubine in early sources.