Fort Brockhurst was built in 1858 and formed part of the Gosport Advanced Lines, a scheme of defences that were built to prevent a hostile force advancing down the peninsula and attacking Portsmouth Harbour. Developments in artillery meant it was obsolete before it was completed although the site remained in military use as a depot and barracks.



Gosport is located on the western side of Portsmouth Harbour which, by the seventeenth century, was increasingly being used as a base by the Royal Navy. Although the main docks were in Portsmouth, the naval presence also led to the expansion of Gosport with some of the dockyard facilities built in the town. In 1677 Gosport was enclosed by an earth rampart fronted with a dry moat. In the 1680s two artillery blockhouses - Fort Charles and Fort James (Burrow Island) - were constructed. These were replaced in 1748 by the Gosport Lines, a substantial bastioned rampart fronted by a ditch. These defences remained extant until the mid-nineteenth century. However, in 1852 Napoleon III became Emperor of France prompting fears of a resumption of the Napoleonic Wars. The situation deteriorated in 1858 when France launched the world's first seagoing ironclad warship ('La Gloire'; the Glory) – an armoured vessel outclassed anything in the Royal Navy and threatened Britain’s maritime superiority. Britain, in a state of panic, initiated a Royal Commission to make recommendations on coastal defence. However, before the Commission stood up, defensive plans devised by Colonel William Jervois, Assistant Inspection General of Fortifications were put in motion for the protection of Portsmouth Harbour. The plans included construction of the Gosport Advanced Lines, a series of polygonal land defence forts, located around two miles from the waterfront and intended to prevent an enemy force proceeding down the Gosport peninsula and bombarding the dockyard. Fort Brockhurst was one of five facilities in this line (the others were Fort Elson, Fort Rowner, Fort Grange and Fort Gomer).


Work started on Fort Brockhurst on 31 March 1858 and continued through to completion on 20 December 1862. It was laid out in polygonal arrangement which reflected the latest military doctrine and replaced the bastioned design of earlier forts such as the Royal Citadel. Instead, each fort operated in conjunction with its neighbours and was able to provide supporting fire across the front of the adjacent outposts. Like its identical forts at Grange and Rowner, Fort Brockhurst was designed for an armament of 50 guns although only a portion was ever installed; a report dated 1893 listed eight 7-inch Rifled Breach Loading guns, nine 64-pounder Rifled Muzzle Loading guns and two 0.45-inch Machine Guns. The fort's earth topped rampart was built over casemated barracks that provided accommodation for a garrison of 308 men. Two ramps provided access to the terreplein. Surrounding the fort was a wet ditch which was covered by three caponiers. A triangular shaped salient, known as a redan, extended to the north and was intended to provide flanking fire against any attacking force. A circular Keep, also surrounded by a wet ditch, was located to the rear and redesigned to act as a redoubt should the fort be overrun.


Even before Fort Brockhurst was completed, concerns were being expressed that it was built in the wrong place. Developments in artillery meant that the location of Fort Brockhurst and her sister outposts were simply too close to the dockyard and would be unable to prevent an overland attack getting into effective artillery range of the dockyard. Accordingly the findings of the Royal Commission proposed construction of the Gosport Outer Lines, a series of three forts located two miles in advance of the existing forts. In the end only one of these new outposts - Fort Fareham - was actually constructed as the Government balked at the idea of decommissioning brand new facilities built at vast taxpayer expense. Accordingly Fort Brockhurst, along with her sister forts of the Gosport Advanced Line, remained in commission. The invasion fears came to nothing and thereafter the fort simply served as a base for a variety of military units and as a depot. During World War I it was used as a recruitment and de-mobilisation centre. During World War II it provided transit accommodation and suffered some minor bomb damage during an air-raid. The military disposed of the site in 1957 and it is now in the care of English Heritage.





Allen, R (1976). English Castles. Batsford, London.

Cantwell, A and Sprack, P (2011). The Needles Defences. Gosport.

Coad, J.G (1989). Fort Brockhurst. English Heritage, London.

Dyer, N (2011). British Fortification in the late 19th and early 20th centuries. Fareham.

Jervois, W (1857). Report on completion of the defences of Portsmouth.

King, C.D.J (1983). Castellarium anglicanum: an index and bibliography of the castles in England, Wales and the Islands.  Kraus International Publications.

Moore, D (1992). Fort Brockhurst and the Gomer-Elson Forts. Gosport.

Saunders, A.D (1966). Coastal Defences since the introduction of artillery.


What's There?

Fort Brockhurst is a well preserved and largely unaltered Victorian Fort. The site is in the care of English Heritage but check opening times before travelling as the fort is only periodically opened to the public.

Gosport Advanced Lines. The five forts of the Gosport Advanced Lines were positioned to provide supporting fire to each other thus, whilst not physically connected by a wall or rampart, they provided a complete barrier against any force advancing along the peninsula. The three central forts - Brockhurst, Rowner and Grange - were all configured to the same plan.

Keep. The rear of the fort was dominated by a round Keep surrounded by a wet moat which was intended to provide a redoubt should the fort itself be overrun. However, this inspiration from earlier ages was flawed as the brick walls of the keep would have been extremely vulnerable to artillery fire and, had the garrison abandoned the rest of the fort and its weapons, there would have been some extremely powerful guns available to the attackers.

Keep Caponier. Eight small caponiers projected out from the keep.

Northern Rampart. The fort's northern (right flank) rampart. The earth banks were designed to absorb enemy fire.

Casemated Rampart. The fort's main rampart was built over case-mated barracks which served as the accommodation for the fort's garrison of 308 men.

Ramp. Two earth ramps within the parade ground provided a means of wheeling artillery onto the fort's terreplein.

Caponiers. The flanks of the fort were protected by projecting caponiers that enabled the defenders to fire along the length of the rampart.

Ablution Block.

Victorian Defences Portsmouth. The Victorian doctrine for defence of the United Kingdom was based on the principle that if the Royal Navy could operate unhindered, then any invasion attempt would ultimately fail. Accordingly Portsmouth, along with other key dockyards, was protected by a ring of forts to provide defence from both sea attack and overland assault.

Getting There

Fort Brockhurst is found directly off the A32 Fareham Road. The site is sign-posted. There is a small car park and on-road parking is possible.

Fort Brockhurst

Gunner's Way, PO12 4DS

50.814587N 1.153573W