Amlaíb, son of Sitric Cáech of the Uí Ímair dynasty, was a Norse-Gaelic ruler whose career spanned the Irish Sea. He was twice king of Northumbria at York in the 940s and early 950s, was baptised with King Edmund of England as sponsor, and ruled Dublin for some three decades until 980. Defeated at Tara by Máel Sechnaill, who then took Dublin and freed its Irish hostages, he abdicated and died in religious retirement on Iona. His byname means "sandal".