CASTLETOWN (Manx, Bully Cashtel), a town of the Isle of Man, 10 m. S.W. of Douglas, by the Isle of Man railway. Pop. (1901) 1975. It is picturesquely situated on both sides of a small harbour formed by the outflow of the Silver Burn into Castletown Bay. It was the legal capital of the island until 1862. In the centre of the town stands Castle Rushen, which is said to owe its foundation to the Danish chief, Guthred, in 947–960, though the existing building, which is remarkably well preserved, probably dates from the 14th century. Until the 18th century it was the residence of the lords of Man, and until 1891 served as a prison. The massive keep is square, and is surrounded by an outer wall, with towers and a moat. The council chamber and court-house were built in 1644. In the neighbourhood of the castle is the old House of Keys, where the members of the Manx parliament held their sessions until the removal of the seat of government to Douglas. A lofty Doric column commemorates Cornelius Smelt, lieutenant-governor of the island (d. 1832), near which there is a remarkable sun-dial with thirteen faces, dating from 1720. King William’s College, situated a mile to the north-east of the town, was opened in 1833; but a complete restoration was rendered necessary by fire in 1844, and it was subsequently enlarged. It is the chief educational establishment in the island. At Hango Hill near the town William Christian, receiver-general, who had surrendered the castle, and with it the island, to the parliamentary forces in 1651, was executed in 1663 at the instance of the countess of Derby, who had undertaken to defend it for the king. A small shipping trade is maintained.