In 671 BeornhAeth Sub King Northern Northumbria aka Lothian succeeded Sub King Northern Northumbria aka Lothian.
In 671 King Ecgfrith of Northumbria (age 26) and BeornhAeth Sub King Northern Northumbria aka Lothian defeated at the Battle of the Two Rivers bringing to an end the Pictish rebellion. The location of the battle is not known. Stephen of Ripon described the account in his account of the battle from Vita Sancti Wilfrithi: He slew an enormous number of the people, filling two rivers with corpses, so that, marvellous to relate, the slayers, passing over the rivers dry foot, pursued and slew a crowd of fugitives.
In 685 BeornhAeth Sub King Northern Northumbria aka Lothian died.
[his son] Berhtred Northumbria was born to BeornhAeth Sub King Northern Northumbria aka Lothian.