 The execution of a high-ranking chief caused more than one chief to reconsider his support for such a troublesome monarch.Canute's headaches came to a head in 1085-86, when he decided to invade England and try to take the throne from William I who was old and by some reports failing.As a close relative of Canute the Great, Canute's claim was easily as valid as that of William of Normandy's.