Bernicia was a in British history anglo-saxon Northern kingdom, which had permanently united with its neighbor in the last quarter of the 7th century Deira to the kingdom Northumbria . Bernicia stretched from maybe to River Tees north and eventually reached the Firth of Forth and beyond Solway Firth . It had a royal residence in Bamburgh on the coast and another at Yeavering, some 20 miles inland, where excavations have uncovered an impressive group of buildings .
The first recorded king of Bernicia was Ida , the 547 or c . 558. His grandson Aethelfrith , who reigned from 593 to 616, united Bernicia and Deira and Aethelfrith's successor King Edwin of Deira ruled both kingdoms. Aethelfrith's son Oswald also ruled both kingdoms, but after Oswald's death in 641 his brother managed to reach Bernicia, while other kings were chosen by the Deiranians and ruled independently until 678 .