Olaf Guthfrithson (911-941) was King of Sudreyjar from 934 to 941 (succeeding Gofraid ua Imair and preceding Amlaib Cuaran) and King of Dyflin from 934 to 941 (succeeding Gofraid and preceding Blacaire mac Gofraid).
Biography[]
Olaf Guthfrithson was the son of Gofraid ua Imair, the King of Sudreyjar, and he succeeded his father as King of Sudreyjar in 934. In 937, he established his dominance over the Vikings by Limerick by capturing their king Amlaib Cenncairech; that same year, he allied with Constantine II of Scotland in an attempt to reclaim Northymbre from England. King Aethelstan of England defeated their army at Brunanburh in 937, and Olaf returned to Ireland in 938. After Aethelstan's death the following year, Olaf returned to York and established himself as king with his brother Blacaire mac Gofraid was left as king in Dublin, and, in 939, Olaf agreed to divide England with Edmund I of England. However, the peace agreement was short-lived, and the Vikings reoccupied the Five Boroughs of Derby, Leicester, Lincoln, Nottingham, and Stamford. He died in 941 and was succeeded by his cousin Amlaib Cuaran.