Portsmouth Square Tower

Has been described as a Certain Artillery Fort

There are masonry ruins/remnants remains

NamePortsmouth Square Tower
Alternative Names
Historic CountryHampshire and the Isle of Wight
Modern AuthorityPortsmouth; City of
1974 AuthorityHampshire
Civil ParishPortsmouth

The Square Tower fortification and Governor's residence, now museum. c1494, extensively altered to form a powder magazine c1580 and then the Admiralty Victualling store c1780, reinstated as part of the fortifications mid C19; restored 1978-1985. Stone and brick. Flat stone paved roof with 3 restored mid C19 gun races facing south-west. EXTERIOR: south-west part 1 storey and north-east part 2 storeys. 2 bays. Main entrance facing south-east within enclosed yard has on right a 2-leaf late C20 copy of the original C18 doors with lower panels and vertical iron bars to upper panels set under a segmental stone arch with rusticated voussoirs and jambs. On first floor is a mid C18 2-leaf 20-pane casement. To left at saluting platform level is a late C20 boarded door leading to roof area and to late C20 visitors' viewing balcony. North-west facade has on left a late C20 boarded door set within C15 opening. On right is an C18 2-leaf casement set within C15 opening and further right is a late C20 replica of the original C18 panelled door with vertical iron bars to top panel. First floor has on left a mid C19 2-leaf 4-pane casement and on far right a late C20 glazed infill. On north-east side facing Broad Street is a niche edged with a wreath. This contains a late C20 copy of a gilded lead bust of Charles I by Hubrecht le Sueur (original restored and now deposited in the City Museum). Below are the Royal Arms on a small bracket and the inscription reads "After his travels through all France into Spain and having passed very many dangers both by sea and land he arrived here the 5th day of October 1623". INTERIOR: the late C20 restoration has uncovered Tudor features including two fireplaces and C18 features which include a stone stairway on north-east side running from ground to former basement. (Listed Building Report)

Gatehouse Comments

The Square Tower stands at the south-west end of the High Street. Stone and brick tower standing 9m tall. Built in 1494 as a gun platform and house, it was used as a powder magazine from the late C16 to the early C18. Rebuilt in C19 and used as an admiralty semaphore telegraph station between 1822 and 1833, medieval work mainly buried inside.

- Philip Davis

This site is a scheduled monument protected by law

This is a Grade 1 listed building protected by law

Historic England Scheduled Monument Number
Historic England Listed Building number(s)
Images Of England
Historic England (PastScape) Defra or Monument number(s)
County Historic Environment Record
OS Map Grid ReferenceSZ630992
HyperLink HyperLink HyperLink
Photo by Philip Davis All Rights Reserved
Photo by Philip Davis All Rights Reserved
Photo by Philip Davis All Rights Reserved
Photo by Philip Davis All Rights Reserved

Most of the sites or buildings recorded in this web site are NOT open to the public and permission to visit a site must always be sought from the landowner or tenant.

Calculate Print


  • Osborne, Mike, 2011, Defending Hampshire: The Military Landscape from Prehistory to the Present (Stroud: The History Press) p. 245 (listed in Appendix)
  • Salter, Mike, 2002, The Castles of Wessex (Malvern: Folly Publications) p. 50
  • Saunders, Andrew, 1997, Channel Defences (London; Batsford/English Heritage) p. 57, 119
  • Pettifer, A., 1995, English Castles, A guide by counties (Woodbridge: Boydell Press) p. 88-9
  • Berridge DW., 1985, Restoration of Square Tower, Old Portsmouth (Portsmouth)
  • Barron, W.G., 1985, The Castles of Hampshire and Isle of Wight (Paul Cave) p. 41
  • Lloyd, D.W., 1974, Buildings of Portsmouth and its Environs (Portsmouth) p. 55-59
  • Corney, A., 1965, Fortifications in Old Portsmouth (Portsmouth) p. 15-17



  • Renn, Derek, 1987, 'English fortification in 1485’ Château Gaillard Vol. 13 p. 169-174
  • Kenyon, J.R., 1981 'Early Artillery Fortifications in England and Wales: a Preliminary Survey and Re-appraisal' The Archaeological Journal Vol. 138 p. 220

Primary Sources


  • Dave Hopkins, 2004, Extensive Urban Survey - Hampshire and the Isle of Wight (English Heritage) Download copy