Yarmouth Castle is an artillery fort built by Henry VIII in 1547 to protect Yarmouth Harbour on the Isle of Wight from the threat of French attack. Just under 100 feet (30 m) across, the square castle was initially equipped with 15 artillery guns and a garrison of 20 men. It featured an Italianate "arrow-head" bastion on its landward side; this was very different in style from the earlier circular bastions used in the Device Forts built by Henry and was the first of its kind to be constructed in England.