Portchester Castle was originally the late 3rd century Roman Saxon Shore fort of Portus Adurni, possibly founded by Marcus Aurelius Carausius. In the early 10th century, the fort was turned into a Saxon burgh and excavations found a residence with a hall and a tower, possibly of a 10th century thegn. William the Conqueror granted Portchester to William Maudit, who probably founded the inner bailey in the north-west angle of the fort, when defending its buildings with an L-shaped ditch and a timber palisade. In the early to mid 12th century, William Pont de l'Arche founded the stone castle when flanking the north-west angle with a square great tower. In 1154 King Henry II used the castle as a royal stronghold and an important point of embarkation. Against the west and south walls of the inner bailey, are the remains of King Richard II's Palace, a range of late 13th century royal apartments. From the mid 18th century, the castle was a camp for prisoners of war until 1819, when the army abandoned the fort. 3 miles north-east is Pinsley Motte.