Monument MPM1024 - Portsbridge Fort

Defensive fort on the northern bank of Portscreek. The first known fort was contructed c1600 and would have consisted of earthen ramparts and wooden palisades. This was redesigned in 1688 by Beckman. A more permanent structure designed by Desmartez was built in 1747. The fort appears to have been demolished during the mid-19th century.

Former fort situated on the northern bank of Portscreek, demolished circa mid-19th century. It is probable that there would have been some form of defensive structure on the site since the reign of Henry VIII, although the first known fort was built around 1600. This would have consisted of earthen ramparts with wooden palisades and gates. There would also have been an outwork defense opposite on the southern bank of the creek. The fort was redesigned in 1688 by Chief Military Engineer Sir Martin Beckman, and a third fort designed by John Peter Desmaretz was built on the site in 1747. The latter was a more permanent defensive structure, with earthen ramparts, brick revetted breastwork and timber gatehouses with a drawbridge. Twelve six-pounder guns would have been mounted on platforms. The tollhouse for the turnpike was situated close to the fort's northern entrance. [1]

Although an exact date is not known, Portsbridge fort appears to have fallen into disuse around the mid-19th century when the ring of defensive forts on Portsdown Hill known as 'Palmeston's Follies' were built.

During its history the fort was only attacked once during a small skirmish between Royalist and Parliamentarian forces on the evening of the 12th of August 1642. Parliamentarian troopers under the command of Sir William Waller captured the fort and were able to cross the bridge on to Portsea Island, enabling them to lay siege to, and subsequently capture Southsea Castle and Portsmouth itself [2].

[1] Mitchell, G, 1988, Solent Papers Number 4 ‘Hilsea Lines and Portsbridge

[2] Webb, J, 1969, The Siege of Portsmouth in the Civil War, Issue No.7, Portsmouth Paper’s Series

Webb, J, 1969, The Siege of Portsmouth in the Civil War, Issue No.7, Portsmouth Paper’s Series (Bibliographic reference). SPM73.

Mitchell, G, 1988, Solent Papers Number 4 ‘Hilsea Lines and Portsbridge’ (Bibliographic reference). SPM72.