In 865 the Viking Great Heathen Army landed in East Anglia, and used it as a starting point for an invasion. The East Anglians were forced to buy peace, and the following year the Vikings invaded Northumbria, where they established an obscure Northumbrian man called Egbert as puppet king in 867. They then moved on to Nottingham in Mercia, where they spent the winter of 867–868. Burgred was joined by King Æthelred of Wessex and his brother, the future King Alfred, for a combined attack on the Vikings, but they refused an engagement and in the end the Mercians bought peace with them. The following year, the Vikings conquered East Anglia. They returned to Mercia in 872; two years later they expelled Burgred, and Ceolwulf became king with their support. Ceolwulf was described by the "Anglo-Saxon Chronicle" as "a foolish king's thegn" who was a puppet of the Vikings, but the historian Ann Williams regards this view as partial and distorted: he was accepted as a true king by the Mercians and by King Alfred.