ST. MICHAEL'S MOUNT, a lofty pyramidal island, ex hibiting a curious combination of slate and granite, rising 400 yds. from the shore of Mount's bay, Cornwall, England. It is united with Marazion by a natural causeway passable only at low tide. If its questionable identity with the Mictis of Timaeus and the Ictis of Diodorus Siculus be allowed, St. Michael's Mount is one of the most historic spots in the west of England. It was possibly held by a religious body in the Confessor's time ‘and given by Robert, count of Mortain, to Mount St. Michael, of which Norman abbey it continued to be a priory until the dis solution of the alien houses by Henry V., when it was given to the abbess and Convent of Syon. It was a resort of pilgrims, en couraged by Pope Gregory (11th century). The Mount was cap tured by Henry Pomeroy in the reign of Richard I. John de Vere, earl of Oxford, seized it and held it against the king's troops in 1473. Perkin Warbeck occupied it in 1497. Humphry Arundell,
governor of St. Michael's Mount, led the rebellion of 1549. Dur ing the reign of Queen Elizabeth it was given to Robert, earl of Salisbury, by whose son it was sold to Sir Francis Basset, whose brother, Sir Arthur Basset, held it against the parliament until July 1646. It was sold in 1659 to Colonel John St. Aubyn and is now the property of his descendant Lord St. Leven, who has a residence in the castle. The chapel is extra-diocesan.
Many relics are preserved in the castle. The chapel of St. Michael, a beautiful 15th-century building, has an embattled tower. A few houses are built on the hillside facing Marazion, and a spring supplies them with water. The harbour, widened in 1823 to allow vessels of 500 tons to enter, has a pier dating from the 15th century. Pop. (1921) 59.