In 865 the Danish Vikings changed their tactics. A large army made up of many smaller bands landed in East Anglia. For over a decade they remained in England destroying entire kingdoms as they went. The Danes spent the winter in East Anglia. The local people bought peace with the Vikings by supplying them with horses. After a year they moved northwards to Northumbria now a mounted army. They captured York and defeated two Northumbrian kings, Aella and Osbert, who joined forces to attack the Danes. Both kings were killed. In 867 they appointed a client-king named Ecgberht over the Northumbrians. In the fall of that year they moved south into Mercia. The Danes made their winter camp at Nottingham. In 868 Burgred, the King of Mercia, asked King Ethelred of Wessex and his brother Alfred for their help against the Danes. The Danes did not fight but allowed the Mercians to pay them for peace. 