The treaty between Wessex, Guthrum and the East Angles divided England, with Alfred and Wessex retaining the west, while the east (between the Thames and Tees rivers) was to be Viking territory
Athelstan, king of Wessex, pushed the boundaries of his kingdom to their furthest extent, until he could rightfully be described as the king of England
Aethelred ordered the massacre of all Vikings living in England on St Brie's Day, including the sister of the current king of Norway: Swein/Swen Forkbeard