Instead, Rædwald raised an army and marched against Æthelfrith, and around 616 Æthelfrith was defeated and killed at the Battle of the River Idle (on the east side of the River Idle) by an army under Rædwald; Bede says that Æthelfrith had the inferior army, because Rædwald had not given him time to bring all his forces together.Bede, H.E., II, 12. While presented by Bede as being fought simply over the issue of Edwin, this war may have actually involved questions of power and territory between the two rulers.Kirby, pages 52 and 61. Following Æthelfrith's death, Edwin became king not just of Deira but of Bernicia as well; Æthelfrith's sons Eanfrith, Oswald, and Oswiu fled to the north.See Bede, H.E., II, 12; H.E. III, 1 (which mentions the exile of Æthelfrith's sons among the Scots and Picts); and the Anglo-Saxon Chronicle, manuscript E, under the year 617. The ASC (E) lists the sons of Æthelfrith as follows: Eanfrith, Oswald, Oswiu, Oslac, Oswudu, Oslaf and Offa. Thus Æthelfrith's death in battle has been seen as causing "a near total revolution in the politics of what is now northern England". After Edwin was killed in 633 at the Battle of Hatfield Chase, Eanfrith temporarily regained power in Bernicia, and subsequently Oswald restored the Bernician line of Æthelfrith to power in both Bernicia and Deira. After this point, Æthelfrith's descendants continued to rule until the first part of the eighth century.Kirby, page 52.
Instead, Rædwald raised an army and marched against Æthelfrith, and around 616 Æthelfrith was defeated and killed at the Battle of the River Idle (on the east side of the River Idle) by an army under Rædwald; Bede says that Æthelfrith had the inferior army, because Rædwald had not given him time to bring all his forces together.Bede, H.E., II, 12. While presented by Bede as being fought simply over the issue of Edwin, this war may have actually involved questions of power and territory between the two rulers.Kirby, pages 52 and 61. Following Æthelfrith's death, Edwin became king not just of Deira but of Bernicia as well; Æthelfrith's sons Eanfrith, Oswald, and Oswiu fled to the north.See Bede, HE., II, 12; H.E. III, 1 (which mentions the exile of Æthelfrith's sons among the Scots and Picts); and .the Anglo-Saxon Chronicle, manuscript E, under the year 617. The ASC (E) lists the sons of Æthelfrith as follows: Eanfrith, Oswald, Oswiu, Oslac, Oswudu, Oslaf and Offa. Thus Æthelfrith's death in battle has been seen as causing "a near total revolution in the politics of what is now northern England". After Edwin was killed in 633 at the Battle of Hatfield Chase, Eanfrith temporarily regained power in Bernicia, and subsequently Oswald restored the Bernician line of Æthelfrith to power in both Bernicia and Deira. After this point, Æthelfrith's descendants continued to rule until the first part of the eighth century.Kirby, page 52.