Olaf Guthfrithsson

Olaf Guthfrithsson (d. 941), king of Dublin. Olaf succeeded to the throne in 934. His first years as ruler established his position in Ireland. This freed him for an attempt to regain the Viking kingdom of York, from which his father had been expelled in 927 by Athelstan. But Olaf's grand coalition was cut to pieces by Athelstan at Brunanburh (937). After Athelstan's death in 939, Olaf renewed the struggle, occupied York, harried Mercia, sacked Tamworth, and forced Edmund to concede all the lands north-east of Watling Street. He was killed the following year near Dunbar, and his successors were unable to hold the territories he had won back.