PORCHESTER, or PORTCHESTER, a parish in the hundred of PORTSDOWN, Portsdown division of the county of SOUTHAMPTON, 2 miles (E.S.B.) from Fareham, containing 757 inhabitants. This place, the ancient Caer Peris of the Britons, and the Portus Magnus of the Romans, was by the Saxons called Port ceastre, either from the castle which defended its spacious harbour, or from Port, a Saxon chief, who landed here with his two sons, Bieda and Maegla, and having obtained a settlement in this part of the island, assisted Cerdic in establishing the kingdom of the West Saxons. A castle of great strength was erected on the old Roman works, which was greatly enlarged, or more probably rebuilt, soon after the Conquest; and previously to the destruction of the harbour, on the retiring of the sea, this place was the principal station of the British navy, subsequently removed to Portsmouth. Porchester castle is situated on a neck of land projecting for a considerable way into the sea: the walls, which are from eight to twelve feet in thickness, and eighteen feet .high, enclose a quadrangular area of nearly five acres, and are defended by numerous towers, and surrounded by a broad and deep moat: the keep is a strong square. building, one hundred and fifteen feet in length, and sixty-five feet in breadth, with four towers, the largest of which forms the northwest angle; it contains many spacious rooms, of which some are vaulted with stone, and one appears to have been the chapel: the entrance to the outer area is through massive Norman towers on the east and west sides. The ancient parish church of St. Mary is within the outer area of the castle, of which several of the towers and a considerable portion of the walls are now in ruins; the castle, during the late war, was appropriated as a place of confinement for prisoners of war. The village of Porchester, called by way of distinction Porchester-street, extends for about a mile on the road to Fareham, and contains several neat houses: the publicans, by charter of Elizabeth, enjoy exemption from having soldiers billeted in their houses. The living is a discharged vicarage, in the archdeaconry and diocese of Winchester, rated in the king's books at £6, endowed with £200 royal bounty, and in the patronage of the Crown. The church, dedicated to St. Mary, is an ancient and venerable cruciform structure, in the Norman style of architecture, with a low central tower; the south transept has been destroyed, and the chancel, which is small, is of later date, and has an east window of three lights, in the later style of English architecture; -the west front is-in-good preservation, and exhibits a fine specimen of the Norman style.