Viking Age by a Viking leader called Bagsecg and his five earls. Aided by the Great Heathen Army (which had already overrun much of England from its base in Jorvik), Bagsecg's forces, and Halfdan's forces (through an alliance), the combined Viking forces raided much of England until 871, when they planned an invasion of Wessex. On 8 January 871, Bagsecg was killed at the Battle of Ashdown along with his earls. As a result, many of the Vikings returned to northern England, where Jorvic had become the centre of the Viking kingdom, but Alfred of Wessex managed to keep them out of
Halfdan Ragnarsson led by Bagsecg, bolstering the ranks of Halfdan's army. According to the "Anglo-Saxon Chronicle", the Danes battled the West Saxons nine times, including the Battle of Ashdown on 8 January 871. However, the West Saxons could not be defeated, and Halfdan accepted a truce from Alfred, newly crowned king of Wessex. The Army retreated to the captured town of London and stayed there over the winter of 871/872. Coins minted in London during this period bear the name Halfdan, identifying him as the leader of the army. In autumn of 872 the Army returned to Northumbria to quell a revolt