York is an important town in Northumbria. One of the biggest town in England, it was also the capital of northern Northumbria and later on, an important Viking stronghold following the sack of York, that was decided by Ivar the Boneless in order to establish a Norse stronghold located next to the coast thanks to which vikings could raid deeper in England. The Saxons tried to take the town twice but were pushed back by the great heathen army. Ivar left jarl Olavsonn as his lieutenant in the city. King Harald, before his campaign against Wessex, arrived in York at the head of his troops, forming an alliance with Jarl Olavsonn, both agreeing to plunder and attack Wessex together after which they would overthrow King Ivar.