The forces of Olaf Guthfrithson were defeated by the English led by Æthelstan at a battle fought in which year ?
Olaf Guthfrithson: Olaf Guthfrithson (Old Norse: "Óláfr Guðrøðsson" ; ; Old Irish: "Amlaíb mac Gofraid" ; died 941) was a Viking leader who ruled Dublin and Viking Northumbria in the 10th century.
i don't know