At the end of 870 they launched an attempt to conquer Wessex and marched from East Anglia to Reading, arriving on about 28 December.

Three days later they sent out a large party under two earls to forage and reconnoitre, and it was met at Englefield by an army of local levies under the command of Æthelwulf, Ealdorman of Berkshire.

After one of the earls was killed and a large part of the Danish army was overthrown, the Viking force broke and ran.

Four days later, the main West Saxon army, led by King Ethelred and his brother, the future King Alfred the Great, attacked the main Danish encampment at Reading and were bloodily repulsed in the Battle of Reading.

Soon after Easter, which fell on 15 April in that year, Æthelred died and was succeeded by Alfred.