Upon successfully raiding York, Ivar decided to make York a Norse stronghold they could use to raid deeper into England. The Saxons tried to take back the town twice, but were pushed back by the Vikings. Ivar left Jarl Olavsonn as his lieutenant and the commander in the city. King Harald arrived in York at the head of his troops. Harald formed an alliance with Jarl Olavsonn, and they agreed to plunder and attack Wessex together before returning to Kattegat to overthrow King Ivar.
York is the head settlement of historic Yorkshire. It was founded by the Romans as Eboracum in 71 AD, and became the capital of the Roman province of Britannia Inferior. In 866 AD, Vikings raided and captured York. As a thriving Anglo-Saxon metropolis and prosperous economic hub, York was a clear target for the Vikings. Ivar the Boneless and Halfdan's Scandinavian forces attacked the town on All Saints' Day when most of York's leaders were in the cathedral. After it was conquered, the city was renamed to Jórvík. It became the capital of Viking territory in Britain, and at its peak, had more than 10,000 inhabitants. Norse coinage was created at the Jórvík mint, and evidence of a variety of craft workshops have been discovered. The town was part of an international trading network. Under Viking rule, the city became a major river port and part of the extensive Viking trading routes throughout Northern Europe. The last ruler of Jórvík was Eric Bloodaxe, who was driven from the city inn 954 AD by King Eadred.