Olaf III Guthfrithson

Olaf Guthfrithson
King of Dublin
Reign	934–939
Predecessor	Gofraid ua Ímair
Successor	Blácaire mac Gofraid
King of Northumbria
Reign	939–941
Predecessor	Æthelstan (as King of the English)
Successor	Olaf Cuaran
Died	941
Burial	Auldhame, Scotland (possibly)
Issue	Cammán Gofraid Ímar
House	Uí Ímair
Father	Gofraid ua Ímair

Olaf Guthfrithson (Old Norse: Óláfr Guðrøðsson; Old English: Ánláf; Old Irish: Amlaíb mac Gofraid; died 941) was a Viking leader who ruled Dublin and Viking Northumbria in the 10th century. He was the son of Gofraid ua Ímair and great-grandson of Ímar, making him one of the Uí Ímair. Olaf succeeded his father as King of Dublin in 934 and succeeded in establishing dominance over the Vikings of Limerick when he captured their king, Amlaíb Cenncairech, in 937. That same year he allied with Constantine II of Scotland in an attempt to reclaim the Kingdom of Northumbria which his father had ruled briefly in 927. The forces of Olaf and Constantine were defeated by the English led by Æthelstan at the Battle of Brunanburh.

Olaf returned to Ireland in 938 but after Æthelstan's death the following year Olaf left for York where he was quickly able to establish himself as king, with his brother Blácaire mac Gofraid being left to rule in Dublin. Olaf and Æthelstan's successor Edmund met in 939 at Leicester where they came to an agreement regarding the division of England between them. This agreement proved short-lived, however, and within a few years Vikings had occupied the Five Boroughs of Derby, Leicester, Lincoln, Nottingham and Stamford. Olaf died in 941 was succeeded in Northumbria by his cousin Olaf Cuaran. At the time of his death, the Irish annals title him "king of Danes" and "king of the Fair Foreigners and the Dark Foreigners".

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