Page "Northumbria" Paragraph 13

After Edwin's death, Northumbria was split between Bernicia, where Eanfrith, a son of Aethelfrith, took power, and Deira, where a cousin of Edwin, Osric, became king.

Cumbria tended to remain a country frontier with the Britons.

Both of these rulers were killed during the year that followed, as Cadwallon continued his devastating invasion of Northumbria.

After the murder of Eanfrith, his brother, Oswald, backed by warriors sent by Domnall Brecc of Dál Riata, defeated and killed Cadwallon at the Battle of Heavenfield in 634.