HMNB Portsmouth

Wikipedia contributors · CC BY-SA · EN · 04/10/2026

His Majesty's Naval Base, Portsmouth (HMNB Portsmouth) is one of three operating bases in the United Kingdom for the Royal Navy (the others being HMNB Clyde and HMNB Devonport). Portsmouth Naval Base is part of the city of Portsmouth; it is located on the eastern shore of Portsmouth Harbour, north of the Solent and the Isle of Wight. For centuries it was officially known as HM Dockyard, Portsmouth: as a Royal Navy Dockyard, Portsmouth functioned primarily as a state-owned facility for building, repairing and maintaining warships; for a time it was the largest industrial site in the world.

From the 1970s, the term 'Naval Base' began to be used for Portsmouth (and other Royal Dockyards), acknowledging a greater focus on personnel and support elements alongside the traditional industrial emphases. In 1984 Portsmouth's Royal Dockyard function was significantly downsized and downgraded, and was formally renamed the 'Fleet Maintenance and Repair Organisation' (FMRO). The FMRO was privatised in 1998; in 2002, shipbuilding (which had not taken place on site since the late 1960s) resumed in the form of block construction, but this again ceased in 2014.

Today, Portsmouth is the home base for two-thirds of the Royal Navy surface fleet, including the two aircraft carriers, HMS Queen Elizabeth and HMS Prince of Wales. Naval logistics, accommodation and messing are provided on site, with personnel support functions (e.g. medical and dental; education; pastoral and welfare) provided by Defence Equipment and Support. Other functions and departments, e.g. Navy Command Headquarters support staff, are also accommodated within the Naval Base. The base is additionally home to a number of commercial shore activities, including the ship repair and maintenance facility operated by BAE Systems Maritime Services.

The base is the oldest in the Royal Navy, and it has been an important part of the Senior Service's history and the defence of the British Isles for centuries. It is home to one of the oldest surviving drydocks in the world. The former Block Mills are of international significance, having been the first factory in the world to employ steam-powered machine tools for mass production. The Royal Naval Museum has been on the site since 1911. In 1985 a partnership between the Ministry of Defence and Portsmouth City Council created the Portsmouth Naval Base Property Trust to manage part of the historic south-west corner of the Naval Base, under a 99-year lease, as an heritage area, the Portsmouth Historic Dockyard. It allows members of the public to visit important maritime attractions such as Mary Rose, HMS Victory, HMS Warrior and the National Museum of the Royal Navy.

Functioning base

Senior personnel

The Naval Base Commander (NBC) since September 2024 is Commodore Marcel Rosenberg. The harbour is under the control of the King's Harbour Master (KHM), who is the regulatory authority of the Dockyard Port of Portsmouth, an area of approximately 50 sqmi that encompasses Portsmouth Harbour and the Eastern Solent. KHM Harbour Control is based in the Semaphore Tower building. Shipping movements are handled by a team of admiralty pilots headed by the Chief Admiralty Pilot.

In 1836 the Commander-in-Chief, Portsmouth was given accommodation within the Dockyard (in Admiralty House) and in 1889 he was given HMS Victory to be his ceremonial flagship. These privileges were inherited by the Commander-in-Chief Naval Home Command (whose post was combined with that of Second Sea Lord in 1994), who continued to fly his flag from HMS Victory until 2012. That year the post of Commander-in-Chief reverted to the First Sea Lord, and with it the use of Victory as flagship. The Second Sea Lord is now based at the Henry Leach Building on Whale Island, which is also the headquarters of the Fleet Commander.

List of based ships

Some of the following ships (e.g. the patrol vessels) are not based in Portsmouth, but form part of the Portsmouth Flotilla.

First-rate ship of the line

HMS Victory

Queen Elizabeth-class aircraft carriers

HMS Queen Elizabeth

HMS Prince of Wales

Type 45 destroyers

HMS Daring – completing refit; inactive for nearly 8 years as of late 2025

HMS Dauntless

HMS Diamond

HMS Dragon

HMS Defender – entered refit in 2023, scheduled for major upgrade work until 2026

HMS Duncan

Hunt-class mine countermeasures vessels

HMS Ledbury

HMS Cattistock

HMS Brocklesby

HMS Middleton

HMS Hurworth

Mine countermeasures mothership for autonomous systems

HMS Stirling Castle (former Royal Fleet Auxiliary vessel based in Portsmouth from mid-2025 as "mothership" of autonomous vessels from Mine Threat and Exploitation Group)

River-class patrol vessels

HMS Tyne – Fishery protection vessel

HMS Severn – Fishery protection vessel

HMS Mersey – Fishery protection vessel

HMS Forth

HMS Medway – forward deployed to the Falkland Islands as of early 2026

HMS Trent

HMS Tamar – forward deployed to the Indo-Pacific region since 2021, with primary logistics hub at the British Defence Singapore Support Unit in Singapore

HMS Spey – forward deployed to the Indo-Pacific region since 2021, with primary logistics hub at the British Defence Singapore Support Unit in Singapore

Cutlass-class patrol vessels

HMS Cutlass – permanently assigned to the Gibraltar Squadron

HMS Dagger – permanently assigned to the Gibraltar Squadron

Archer-class patrol vessels

HMS Blazer – Southampton Universities Royal Naval Unit

HMS Exploit – Birmingham Universities Royal Naval Unit

HMS Puncher – London Universities Royal Naval Unit

HMS Ranger – Sussex Universities Royal Naval Unit

HMS Smiter – Oxford Universities Royal Naval Unit

Experimental vessel

XV Patrick Blackett (since 2022) – experimental vessel in RN service

Defence Dive School/Fleet Diving Unit Portsmouth

3× Sea-class 15 m diving support boats

Portsmouth Historic Dockyard

Portsmouth Historic Dockyard is the name given to the portion of the base which is open to the public; it plays host to:

The Mary Rose Museum, containing the raised wreck of the Tudor carrack Mary Rose.

HMS Victory, Nelson's flagship at Trafalgar, which (whilst still being in commission) is also open to the public.

HMS Warrior, the first ocean-going Ironclad (built at Blackwall on the River Thames in 1860 and now moored alongside the dockyard).

HMS M33, a World War I monitor.

The National Museum of the Royal Navy, Portsmouth, one of the world's leading maritime museums: galleries include the Nelson Gallery, the Sailing Navy Gallery and the Hear My Story Gallery; exhibits include the Trafalgar Sail (the foretop sail of Victory used at the Battle of Trafalgar, 1805).

The Victory Gallery, telling 'the untold stories behind HMS Victory'''; it also contains the museum's Figurehead Collection and W. L. Wyllie's panorama painting of the Battle of Trafalgar.

The Dockyard Apprentice exhibition in Boathouse 7 (presented by the Portsmouth Royal Dockyard Historical Trust) which tells the story of the Dockyard itself and working life within it.

Portsmouth Harbour Tours, providing boat tours and indicating current naval vessels moored around the harbour.

Boathouse 4, which tells the 'forgotten story' of the small boats of the Navy and is an active boat building and restoration site.

Portsmouth Historic Quarter Trust

The Portsmouth Naval Base Property Trust was established in 1985 (by the Ministry of Defence, English Heritage and Portsmouth City Council); it was granted a 99-year lease on the 12-acre site now known as Portsmouth Historic Dockyard, and this area was then fenced off from the working part of the dockyard. In 2009 it acquired in addition the leasehold of Priddy's Hard (a former RN Armament Depot on the other side of the harbour). In 2024 the charity was renamed Portsmouth Historic Quarter Trust; its main offices are in the former Police Superintendent's house, next to the Porters' Lodge.

The Trust functions as the custodian of 'historic buildings, boats and spaces in and around Portsmouth Harbour', aiming to preserve and develop the 'rich maritime heritage and vibrant culture' of its sites, through 'building regeneration, boat restoration, volunteer activity and community collaboration'. It manages the areas of the Historic Dockyard that can be accessed free of charge, including Boathouse 4, Boathouse 7 and various outdoor spaces.

The trust has long sought to extend the area of the Historic Dockyard to cover Dry Docks 4 and 5 and the historic Block Mills building (among others). In 2015 an architectural design competition for the project was won by Latz and Partner; however, the Ministry of Defence subsequently indicated that property to the north of the Mary Rose will not now be ceded for several years at least, due to the site's proximity to the berth of the new Queen Elizabeth-class aircraft carriers.

History

Along with Woolwich, Deptford, Chatham and Plymouth, Portsmouth has been one of the main Royal Navy Dockyards or Bases throughout its history.

Medieval period

Richard I ordered construction of the first dock on the site in 1194, while his successor John added walls around the area in 1212. The docks were used by various kings when embarking on invasions of France through the 13th and 14th centuries, including the Saintonge War in 1242. Edward II ordered all ports on the south coast to assemble their largest vessels at Portsmouth to carry soldiers and horses to the Duchy of Aquitaine in 1324 to strengthen defences.

Tudors

The first recorded dry dock in the world was built in Portsmouth by Henry VII in 1495. The first warship built here was the Sweepstake of 1497; of more significance were the carracks Mary Rose of 1509 and Peter Pomegranate of 1510—both were rebuilt here in 1536. The wreck of the Mary Rose (which capsized in 1545, but was raised in 1982) is on display in a purpose-built museum. A fourth Tudor warship was the galleass Jennett, built in 1539 and enlarged as a galleon in 1559.

The appointment of one Thomas Jermyn as Keeper of the Dock at Portsmouth is recorded in 1526, with a Clerk of the Stores being appointed from 1542. Contemporary records suggest that the dry dock was enlarged and rebuilt in 1523 in order to accommodate the Henry Grace à Dieu (the largest ship of the fleet at that time); but a hundred years later it is described as being filled with rubble.

Following the establishment of Chatham Dockyard in the mid-1500s, no new naval vessels were built here until 1648, but ships from Portsmouth were a key part of the fleet that drove off the Spanish Armada in 1588.

Seventeenth century

Naval shipbuilding at Portsmouth recommenced under the English Commonwealth, the first ship being the eponymous fourth-rate frigate Portsmouth launched in 1650. (Portsmouth had been a parliamentarian town during the civil war.) A resident Commissioner was first appointed in 1649; fifteen years later the Commissioner was provided with a house, and extensive gardens, at the centre of the yard. A new double dry dock (i.e. double the standard length so as to accommodate two ships at once) was built by the Commonwealth government in 1656, on what was then the tip of land at the north-west corner of the yard. It was joined by a single dry dock, just to the south; the yard's one shipbuilding slip (completed in 1651) stood between the two docks. These would all have been built of timber, rather than stone.

By 1660 the dockyard had, in addition to these large-scale facilities for shipbuilding and repairs, a new rope house (1,095 ft in length) and a variety of small storehouses, workshops and dwellings arranged around the site, which was now enclosed by a wooden palisade. After the Restoration, there was continued investment in the site with the excavation of a new mast pond, begun in 1664, alongside which a mast house was built in 1669. Between 1665 and 1668 Bernard de Gomme fortified the dockyard with an earthen rampart (complete with one bastion and two demi-bastions), as part of his wider fortification of Portsmouth and Gosport.

Dummer's pioneering engineering works

As France began to pose more of a military threat to England, the strategic importance of Portsmouth grew. In 1689, Parliament ordered a new dry dock to be built there, large enough to accommodate the latest first-rate and second-rate ships of the line (which were too big for the existing docks). Work began in 1691; as with all subsequent extensions to the dockyard, the new works were built on reclaimed land (on what had been mud flats, to north of the old double dock) and the civil engineering involved was on an unprecedented scale.

The work was entrusted to Edmund Dummer, naval engineer and surveyor to the Navy Board. His new dry dock (the "Great Stone Dock" as it was called) was built to a pioneering new design, using brick and stone rather than wood and with an increased number of 'altars' or steps (the stepped sides allowed shorter timbers to be used for shoring and made it much easier for shipwrights to reach the underside of vessels needing repair). Extensively rebuilt in 1769, the Great Stone Dock is now known as No.5 dock.

Along with the new dock, Dummer proposed that two wet docks (non-tidal basins) be built: the first ("Lower") Wet Dock was entered directly from the harbour and provided access to the Great Stone Dock; since much expanded, it remains in place (now known as "No. 1 Basin"). The second ("Upper") Wet Dock was entered by way of a channel. To empty the dry dock, Dummer designed a unique system which used water from the Upper Wet Dock to drive a water-wheel on the ebb tide, which in turn powered a set of pumps. (At high tide, an auxiliary set of pumps was used, powered by a horse gin.)

Source and attribution

Adapted from “HMNB Portsmouth” by English Wikipedia contributors. Main paragraphs and sections are retained; tables, reference markers and technical markup are omitted. This is an encyclopedic adaptation, not a personal review. Original revision and contributor history ↗. Text is shared under CC BY-SA 4.0 ↗. Check current visitor access, tickets and transport with the relevant operator.