He held extensive land from his cousin, Duke William the Bastard, but lost it following his unsuccessful rebellion in the late 1040s.
[2] As his mother was the daughter of Richard II, Duke of Normandy, Guy was sent to be raised at the Norman court in the early 1040s.
[4] In the late autumn of 1046 the disorder in Normandy which had ravaged the duchy for several years began to crystallize into a coordinated assault upon the young William.
As one of the possible successors to the dukedom in 1035, Guy became the prime mover in this revolt, and was able to rally the support of a very powerful group of Norman magnates.
[6] According to William of Poitiers, Guy either aimed at the ducal throne, which would have been unusually ambitious, or wanted to secure the greater part of the duchy for himself.