During Edward the Confessor’s time, Hanworth was a sparsely populated manor and parish held by Ulf, a "huscarl" of the King. Huscarls were the bodyguards of Scandinavian Kings and were often the only professional soldiers in the Kingdom. The majority of huscarls in the kingdom were killed at Hastings in 1066, and William the Conqueror granted Hanworth to Robert under Roger de Montgomery, the Earl of Arundel and Shrewsbury. After his death, his second son held the land until his death in the Mowbray conspiracy of 1098, after which it passed to his eldest son, Robert de Bellesme, who also rebelled against the Crown in 1102 with the result that the lands were confiscated.
