Immediately Egbert sent his son Athelwulf with an army to overthrow Baldred, the Mercian sub-king in Kent. As a result, all of Kent, Surrey, Sussex and East Anglia submitted to Egbert. Beornwulf tried to recover East Anglia later the same year and was killed in the attempt. Kent, Surrey and Sussex remained a part of the kingdom of Wessex from this time on. Egbert appointed his son Athelwulf as sub-king of Kent which included all the new territories of Wessex.