Battle of Brunanburh
（重定向自Brunanburh）
The Battle of Brunanburh was fought in 937 between Æthelstan, King of England, and an alliance of Olaf Guthfrithson, King of Dublin; Constantine, King of Scotland; and Owen, King of Strathclyde.
Following an unchallenged large-scale invasion of Scotland by Æthelstan in 934, possibly launched because of a peace treaty violation by Constantine, it became apparent that Æthelstan could only be defeated by an allied force of his enemies. Olaf led Constantine and Owen in the alliance.