 Hubert was a minor landowner who had become King John's household chamberlain while still a prince, and went on to become an increasingly powerful royal official once King John inherited the throne.Hubert began to upgrade his new castles, starting with Grosmont, where he rebuilt the hall block in stone.Hubert was captured fighting the French in 1205 and, while he was imprisoned, King John took back the castles and gave them to William de Braose, one of Hubert's rivals.