Sitric Cáech
Sitric Cáech or Sihtric Cáech or Sigtrygg Gále, was a Hiberno-Scandinavian Viking leader who ruled Dublin and then Viking Northumbria in the early 10th century. He was a grandson of Ímar and a member of the Uí Ímair. Sitric was most probably among those Vikings expelled from Dublin in 902, whereafter he may have ruled territory in the eastern Danelaw in England. In 917, he and his kinsman Ragnall ua Ímair sailed separate fleets to Ireland where they won several battles against local kings. Sitric successfully recaptured Dublin and established himself as king, while Ragnall returned to England to become King of Northumbria. In 919, Sitric won a victory at the Battle of Islandbridge over a coalition of local Irish kings who aimed to expel the Uí Ímair from Ireland. Six Irish kings were killed in the battle, including Niall Glúndub, overking of the Northern Uí Néill and High King of Ireland.