[3] A significant number of Georgian, Victorian and Edwardian former hospital buildings are being preserved on the site; they are currently (2024) in the process of being converted to a variety of residential, business, retail and leisure uses.

If necessary, on-shore premises could be hired to serve as temporary 'sick quarters', beds might be reserved for naval use in the main London hospitals and civilian surgeons engaged under contract.

In a twelve-month period in 1739-40, however, nearly 17,000 sick and wounded seamen came ashore in Portsmouth and Plymouth as a result of the War of Jenkins' Ear, and the old systems of treatment and care were unable to cope.

Eventually the Admiralty concurred that they would indeed be a good investment; and in 1744 an Order in Council was issued for the establishment of Naval Hospitals close to Portsmouth, Plymouth and Chatham.

[1] The Admiralty selected and acquired the site for the Portsmouth hospital in 1745: Haslar Farm (whose name came from Anglo-Saxon Hæsel-ōra English: Hazel Bank).

The first hundred patients were admitted on 23 October that year, but the hospital was still unfinished; construction continued until 1762, when the two parallel side wings were finished.

Instead a detached chapel, dedicated to St Luke, was constructed at what would have been its centre-point;[12] (within its pediment an original hour-striking clock by Colley of London, dated 1762, continues to do service).

[13] Built on a peninsula, the hospital's guard towers, high brick walls, and bars and railings throughout the site were all designed to stop patients, many of whom had been press ganged, from going absent without leave.

In that time he played a major part in discovering a cure for scurvy, not least through his pioneering use of a double blind methodology with Vitamin C supplements (limes).

[19] At the same time 12 ft (3.7 m) high railings were installed across the fourth (open) side of the quadrangle to prevent desertions, and the ground floor windows of the wards were barred.

[11] By the end of the century the senior staff at Haslar are listed as a Governor and three Lieutenants, three Physicians, three Surgeons, the Agent, the Steward, a Dispenser and a Chaplain.

[9] In 1805 the medical staff of the naval hospitals became somewhat more integrated into Royal Navy as a whole: they were given a uniform and relative rank, and clearer conditions of appointment.

[24] To give them a view of the Solent, which lay beyond the high walls of the airing ground adjacent to the Asylum, Anderson created two grass-covered mounds topped by summer houses[25] (one of which still survives).

[26] In the 1820s a library was established at Haslar and a museum of specimens from around the world, both created at the instigation of Sir William Burnett, which the Admiralty continued to add to over the years.

[20] By the early 1850s the staff consisted of:[28] To provide fresh water for the hospital a 146 ft (45 m) well had been sunk in the 18th century (on what later became the site of an adjacent naval facility: Haslar Gunboat Yard).

[11] In 1854 the use of female nurses in the naval hospitals ceased; for the next thirty years their place was taken by men (most of whom were pensioners, discharged from active service).

Working alongside the Sick Berth Staff, and supervising them in their duties, were a new female corps of trained and experienced Nursing Sisters, recruited from civilian service.

In place of the Captain-superintendent and Lieutenants, the senior medical officer of the hospital (who was now called the Inspector General) regained administrative oversight.

[20] A separate block was opened in May 1904 for the treatment of sick officers; previously they had been treated in their own designated rooms within the main hospital building.

[8] In 1993, following on from the Options for Change review at the end of the Cold War, a decision was taken to cut the number of military hospitals in the UK from seven to three (one for each Service).

[37] The following year, as part of Front Line First, it was announced that two more hospitals would close, leaving only Haslar (which would be reconstituted as a Joint Services institution).

[12] To mark the handover of control to the National Health Service the military medical staff "marched out" of the hospital, exercising the unit's rights of the freedom of Gosport.

[42] On 17 May 2010 an investigation of the hospital's burial ground, by archaeologists from Cranfield Forensic Institute, was featured on Channel 4's television programme Time Team.