Oswiu [SEP] mother
then King of Bernicia; his siblings included older brothers Eanfrith and Oswald and sister Æbbe. Oswiu's mother was likely Æthelfrith's only recorded wife, Acha, a princess of Deira's royal line who is known to have been Oswald's mother. Regardless, his heritage did nothing to endear him to the Deiran nobility; while they accepted Oswald as king apparently on account of his mother, they resisted Oswiu throughout his reign.
At the time of Oswiu's birth, Æthelfrith was at the height of his power. In
Alhfrith
Alhfrith or Ealhfrith (c. 630 – c. 664) was King of Deira under his father Oswiu, King of Bernicia, from 655 until sometime after 664. Appointed by Oswiu as a subordinate ruler, Alhfrith apparently clashed with his father over religious policy, which came to a head at the Synod of Whitby in 664. After this, Alhfrith disappears from the historical record.
Life.
Alhfrith was the oldest son of Oswiu, who became King of Bernicia in 642. His mother was Oswiu's first wife