A monastery existed on St Michael's Mount in the 8th century and in 1042 it became a Benedictine alien priory. In the mid 11th century, it was granted to the French, Mont Saint-Michel, which was an independent Benedictine order. Seized and fortified by Henry de la Pomeray in 1193-4, the Mount was besieged, taken and restored to the monks, by Hubert Walter. In 1337, it was once again seized and fortified by King Edward III and by 1425 it had become a garrisoned fortress. During the War of the Roses, the Lancastrian Earl of Oxford captures the castle and was then besieged for six months in 1472-3. Given to Humphry Arundell at the Dissolution, there was a strong garrison of Royalists present during the Civil War, until it was taken by siege in 1646. Purchased by John St Aubyn in 1659, the construction of a private mansion, absorbed most of the remaining fortified structures. Sadly the only remaining fortifications are near the top of the Mount and consist of two lengths of Tudor curtain wall, with large splayed embrasures and a watch tower on the angle. 15 miles north-east is Carn Brea Castle.