Athelwulf succeeded his father to the throne of Wessex in 839. His father Egbert had done everything he could so that his son would be king after him. He appointed Aethelwulf his sub-king; ruler of the subordinate kingdom of Kent. This gave Athelwulf experience that made him the leading candidate for king after his father. In turn, Athelwulf did the same for his sons to insure they would follow him to the throne. One of the first things he did as king was to appoint his son Athelstan, King of Kent.