Monument record MDO6504 - Portland Castle

An artillery castle, known as Portland Castle, situated along the northern shore of the Isle of Portland. It represents one of a pair (the other is Sandsfoot Castle) of coastal fortifications constructed during the reign of Henry VIII in order to provide protection for the sheltered waters of Weymouth Bay. The two forts are sited on opposite sides of the bay and are inter-visible. Portland Castle has a central citadel which is fan shaped in plan. The structure is composed of ashlar dressed Portland Stone producing a rounded external appearance. The citadel includes a single storey gun room facing across the Romano-British harbour. The gun room was originally roofed and has embrasures for a further battery of five guns protected by an embattled parapet. This also shielded a second battery situated on the roof of the accommodation block. To the south and south east of the citadel was an outer yard which contained two gun platforms. The construction of the fortification followed the advice of a Commission set up by Henry VIII in 1539, in response to a possible French invasion. It was thought to be have been complete by late 1540 and in service by early 1541. During the Civil War the castle was the scene of some fighting, after which it was used as an ordnance store and later a prison. During the 19th century, the citadel was occupied as a residence, when wood panelling was first added to the interior. The structure is Scheduled and Listed Grade I It is also in the care of the Secretary of State and is open to the public

Portland Castle, at the north end of the Island (SY 684743), was built by Henry VIII as part of his coastal defence system against the threat of invasion by France and was in use late in 1540 (L. and P. Henry VIII, xv, 221; no. 502, 2) It cost £4964. 19s. 101/4d. (B.M., Harl. MSS 353, f. 100 v). On plan the castle forms a sector of a circle with a single-storey gun-room backed by a two-storey building with wings radiating east and north west from a central hall. The gun-room has embrasures for a battery of five guns; the embattled parapet over the gun-room protected a second yard on the south side of the castle, bounded a wall formerly with a ditch outside it, contains gun platforms and a 17th-century building which on a plan of 1716 (Min. of P.B. and Wks. 95/2) comprises a brew-house and stable with an extension to the east forming a sutler's house. Outer defences are now represented by one length of bank on the south east side, 30 yds. long, 16 yds. wide and rising to a maximum height of 4 ft.; it was probably part of these outer defences which was described in a survey of 1623 (B.M Harl. MS. 1326 ff. 726-75) as an ould trencher without the wall of the castle and was to be throwne downe. At the same time the Moate was to be repaired; this was presumably the ditch against the wall of the yard which was still indicated on a survey of 1816 (PRO Wks 31/290) but is now completely obliterated.

The castle was the scene of some fighting during the Civil War, after which it was used as an Ordnance store and a prison. In 1660 a new entrance gateway was erected but by 1680 the castle was reported as being ruinous; restoration was carried out under Queen Anne in 1702 (Cal. Treasury Books, XVII pt. i, 108). In the first half of the 19th century it was modernised for residential occupation after being granted to the Rev. John Manning in 1816; he was succeeded by Capt. Charles Manning in 1834. After standing empty for some years the castle has recently been restored by the Ministry for Public Building and Works. <1> <2> <4>

There is a plan of the castle and adjacent ruined work dated 1738 in the Public Record Office. <3>

No change. <9>

History of the castle. <6> <10>

The castle defences and serviceable ordnance following a survey by the Duke of Marlborough in 1715 was deemed so poor that £408-3-10 was required to repair the defences and a further £61-4-0 for the guns. Of the 17 guns in the castle, only one 4pdr was in good condition. <7>

Listed by Cathcart King. <11>

Additional references. <14> <16>

Notes on the state of the castle in 1623. <12>

Coastal fortification. C 1540, one of Henry VIII's castles. Total cost of £4964-19-10d. Portland ashlar, lead and slate roof. Circular keep enclosing octagonal hall, flanked by wings at an obtuse angle, and enclosing a gun platform at upper level, contained in a segmental wall to seaward. A short cranked passageway gives access to the octagonal hall from the W side; on each side of the hall a large rectangular room at each level, that at ground floor to the SE being the former kitchen. The straight enclosing walls have various rectangular openings to splayed jambs, with a continuous weathered string at mid height, and a further string immediately below the bold segmental parapet with wide splayed gun ports. This detail is carried round the upper level of the roofed quarters. The seaward segment is set on a wide splayed glacis, and has 5 segmental-headed deep double-splayed gun ports, below the weathered string at the segmental parapet with 4 gun ports. The gun platform, behind the parapet with its walkway, is in stone flags. Interior: the ground floor has stone flags, and the upper floor is boarded, carried on heavy floor joists and beams, some of these are original. Walls are ashlar, unpainted. The octagonal hall is sub- divided at each level by timber and plaster partitions. The kitchen, to the right, has very deep splayed openings, to former gun-loops, with flat straight-sided inner arches. The great thickness of walls is shown by the dept of reveals to all openings. Various arched fireplaces; stone stairs with flat-slab stone ceilings. Portland Castle was one of a pair with Sandsfoot Castle in Weymouth, across the harbour and c 3km to the N. Portland originally had a defensive moat. In 1623 it had 13 guns, but by the time of the Civil War there were 21 guns. The Castle was held by the Royalists, but yielded in 1646. From 1816 it was occupied by the Manning family, and the adjacent Captain's House was built. In 1870 it reverted to the Crown, and in 1984 became an English Heritage Property in Care. <13>

Results of tree-ring dating on a single timber from Portland Castle, published in 2000. The beam in the Great Hall was thought to date to the original construction of the castle, known to have taken place during the reign of Henry VIII, around AD 1538 - 40. Two cores were taken from the beam. The heartwood-sapwood boundary was evident on both cores, and the most likely felling date range for the timber was found to be AD 1503 - 35. This shows that the beam in the Great Hall is almost certainly original, and that it may possibly have been cut a few years before being used. Analysis of further timbers from this site may allow clarification of this interpretation. <17>

English Heritage produced an updated edition of their guidebook to Portland Castle in 2000. <18>

Remains include: lime kilns and building layers relating to the construction of the castle, Civil War remains in the moat and prehistoric levels with flint and chert artefacts (Bronze Age). <22>

"Portland Bulwark" was built in 1540 as is one of the smallest of the network of Henrician castles. Its defensive position is solely coastal facing and it lacks all round defences. <23>

This site has a diverse and fascinating history beginning with its construction by Henry VIII to protect the anchorage from French and Spanish attack. It was involved in the English Civil War and later in the First and Second World Wars as a seaplane base and for the D-Day preparations respectively. <24>

<1> Symonds, H, 1914, Sandsfoot and Portland Castles, p34 (Article in serial). SWX1623.

<2> Ministry of Works, 1965, Portland Castle Official Guide (Monograph). SWX1951.

<3> HMSO, 1967, Maps and Plans of the Public Record Office, p303 (Monograph). SWX1960.

<4> Royal Commission on Historical Monuments (England), 1970, An Inventory of Historical Monuments in the County of Dorset, Volume II (South East) Part 3, 451-52 (Monograph). SDO150.

<5> Ordnance Survey, Ordnance Survey 1:10,000 scale map, 1974 (Map). SDO17396.

Portland Castle [NR]

<6> Hogg, Ian V, 1974, Coast defences of England and Wales, 1856-1956, 228-9 (Monograph). SWX1958.

<7> Notes and queries for Somerset and Dorset 30, 155-7 (Article in serial). SWX1959.

<8> Department of the Environment, 1978, Department of the Environment (IAM) Ancient Monuments of England (Vol 2), 82 (Monograph). SWX1687.

<9> Baird, James, 1980, Field Investigators Comments JB, F1 JB 07-JUL-80 (Unpublished document). SWX1956.

<10> 1982, The history of the Kings Works Vol 4 : 1485-1660, 399, 404-405, 466-70 (Monograph). SWX1957.

<11> 1983, Castellarium Anglicanum : an Index and Bibliography of the Castles in England, Wales and the Islands., 127 (Index). SWX4013.

<12> Fortress Study Group, 1988, Fort: the international journal of fortification and military architecture, 46-7 (Serial). SDO18973.

<13> DOE (HRR), 17 May 1993, List of Buildings of Special Architectural or Historic Interest: Borough of Weymouth and Portland amendment 1993, 969-1 (Scheduling record). SWX2185.

<14> Wheatley, Genevieve, 1994, A Teachers Handbook to Portland Castle (Monograph). SWX1963.

<15> Woodward, A, 1994, Site of Proposed Medical/Dental Centre, H M S Osprey, Portland, An Archaeological Evaluation and Desk-Top Study (Unpublished document). SWX8680.

<16> DCMS, 1997, Scheduled Monument Notification 1997, 25/09/1997 (Scheduling record). SDO17426.

<17> Bridge, M C, 2000, Tree-ring Analysis of a Timber from Portland Castle, Castleton, Dorset (Unpublished document). SWX8579.

<18> English Heritage, 2000, Portland Castle, Dorset [guide] (Monograph). SDO20559.

<19> Bellamy, P, 2001, Osprey Quay, Portland, Dorset: Archaeological Impact Assessment. (Unpublished document). SWX8592.

<20> Brown, S, 2002, Portland Castle. Archaeological Watching Brief in the Governor's Garden (Unpublished document). SDO15019.

<21> Vartuca, Franco A, 2005, Portland Castle, Castletown, Dorset: programme of archaeological recording (Unpublished document). SDO17183.

<22> Stewart Brown Associates, 2007, Portland Castle. Archaeological Field Evaluation. (Unpublished document). SDO14398.

<23> Harrington, Peter, 2007, The Castles of Henry VIII, 22 (Monograph). SDO18972.

<24> Engish Heritage, English Heritage Members' and Visitors' Handbook 2009/10, 114 (Monograph). SDO20558.

<25> Linford, N, 2013, Portland Castle, Portland Bill, Dorset. Report on Geophysical Survey, November 2012 (Serial). SDO14978.

<26> National Record of the Historic Environment, 451663 (Digital archive). SDO14739.

Record last edited

Jan 22 2025 12:37PM