927 - Athelstan won again

England
King Athelstan of Wessex stormed York and drove out Olaf Sithtricson and Guthfrith. The Kings of Scotland and Strathclyde and the earl of Northumbria recognized Athelstans supremacy and promised not to ally with vikings again, this was now the beginning of the Kingdom of England.
Ireland
Death of Sihtric, king of Dublin

Normandy
 William I Longsword of Normandy became the new duke of Normandy in 927