Æthelred of Wessex of Mercia, appealed to him for help against the Vikings. Æthelred and his brother, the future Alfred the Great, led a West Saxon army to Nottingham, but there was no decisive battle, and Burgred bought off the Vikings. In 874 the Vikings defeated Burgred and drove him into exile. In 870 the Vikings turned their attention to Wessex, and on 4 January 871 at the Battle of Reading, Æthelred suffered a heavy defeat. Although he was able to re-form his army in time to win a victory at the Battle of Ashdown, he suffered further defeats on 22 January at
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,