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
Battle of Marton and that the Danes were initially put to flight, but at the end of the day and after "much slaughter" the Danes remained masters of the field. Among the fallen was Bishop Heahmund. It was the last of the battles known to be fought by Æthelred against the Danes that year, and the defeated King is reported to have died on 15 April 871. Whether he died in battle, or as a result of wounds suffered in battle is unclear. The site of the battle is unknown. Suggestions include the borders of the London Borough of Merton, Merton in Oxfordshire,