937 - Battle of Brunanburh

England
The son of Sigtryg Gale, Olaf Guthfrithson of Dublin(Olaf Kvaran) tried to reestablish the viking supremacy over Northumbria, he conquered York, but shortly after King Athelstan gave him a devastating defeat at the unknown location of  the Battle of Brunanburh. The armies of the Scottish alliance invaded England, possibly through the River Humber. Aethelstan and Edmund marched fasr to meet them. The battle was the largest battle ever fought on English soil up to that point and lasted all day. After some fierce fighting the Anglo-Saxons eventually broke the Viking shield wall and won the battle. Athelstan defeated a coalition of Dublin vikings,Welsh, Scotsmen( led byConstantine II) and Owain`s company of Strathclyde Britons.
Olaf Guthfrithson of Dublin(Olaf Kvaran) later became an English vassal in Northumbria.
The exact location of the Battle of Brunanburh has never been determined, but it almost the marked area within this map