In 920 Sitric left Dublin for Northumbria, with his kinsman Gofraid ua Ímair succeeding him as king in Dublin. That same year Sitric led a raid on Davenport, Cheshire, perhaps as an act of defiance against Edward the Elder, King of the Anglo-Saxons. In 921 Ragnall ua Ímair died, with Sitric succeeding him as King of Northumbria. Though there are no written accounts of conflict, numismatic evidence suggests there was a Viking reconquest of a large part of Mercia in the following few years. An agreement of some sort between the Vikings of Northumbria and the Anglo-Saxons was achieved in 926 when Sitric married a sister of Æthelstan, perhaps Edith of Polesworth. Sitric also converted to Christianity, though this did not last long and he soon reverted to paganism. He died in 927 and was succeeded by his kinsman Gofraid ua Ímair. Sitric's son Gofraid later reigned as king of Dublin, his son Aralt (Harald) as king of Limerick, and his son Amlaíb Cuarán as king of both Dublin and Northumbria.