The blockhouse was replaced in 1539 by an eight-gun battery under the orders of Henry VIII after his divorce from Catherine of Aragon. Blockhouse was supported by secondary fort to the south from 1545 to 1556, named Haselworth Castle, though this was abandoned only eleven years after construction. A plan to move the dockyard from Portsmouth to Gosport in 1627 never came to fruition, though storehouses for the new docks were built on the site. In 1642, during the English Civil War, the fort was used to bombard Portsmouth, which was at the time under Royalist control.
