After the Battle of Hastings the Roman fort at Pevensey was occupied by the Normans. It was given to Robert, Count of Mortain (William's half brother). Robert de Mortain built his castle there. The castle was besieged several times during the 11th–13th centuries. Queen Elizabeth I ordered that it be demolished but the order was ignored. As late as 1942 small additions were made to the castle for the defence of Britain. It became a lookout over the channel for German aircraft during World War II. Today the castle is in the upkeep of English Heritage. 