The battery lies just north of the site of the Old Willis’s Guard Room. It was originally known as Willis’s I, Princess Caroline’s Battery was completed in 1732 and later renamed in honour of Princess Caroline, the third daughter of King George II. It is located at the junction of Willis’s Road and the road leading to Princess Anne’s Battery. The site was originally a Spanish fortification and was first used by the British during the 13^th Siege of Gibraltar.

The 1744 Armament List records three iron 9-pounder guns mounted here. By 1755, the battery featured three embrasures, all facing north, and by 1771 the armament had been reduced to two iron 9-pounders. During the Great Siege the battery’s firepower was significantly upgraded; by 1781 it mounted three 32-pounders and one 13-inch mortar. A report dated the 13^th September 1782 notes that Princess Caroline’s Battery was rendered ineffective in consequence of the heavy bombardment from the attack by the Spanish floating batteries.

Land Front Defences Plan A, 1782. Princess Caroline's Battery is listed as No. 32.

By 1834, the battery’s armament had been reduced to three 24-pounders, which were still in place in 1859. In 1871, trials were conducted here to test the traversing capabilities of a 9-inch rifled muzzle-loading (RML) gun and the strength of its mounting platform. The gun, mounted on an Elswick Ordnance Company carriage and pivoting on a timber and concrete platform, could be easily traversed by one man with a handspike, and even more smoothly with tackle. Ten rounds were fired during these tests, which took place at six different locations. Following the trials, it was reported that this was the only serviceable 9-inch RML gun in Gibraltar. It remained at Princess Caroline’s Battery at least until December 1872, when the site was inspected by the Director of Artillery and Stores.

On the 15^th August 1877, the War Office authorised the reconstruction of the battery to accommodate two 80-pounder RML guns. Construction began on the 20^th October 1877 and was completed by the 31^st March 1879. These guns remained until 1892, when they were replaced by two 64-pounder RML guns on Gibraltar Depression Carriages. These were withdrawn from service in 1905 and dismantled by May of that year. One of these guns can still be seen near the site today.

See Link: 64-pdr 58 cwt RML, Princess Caroline’s Battery

The Battery in 1861 for three 24-pounders.

1877 reconstruction of the battery to accomodate two 80 RML guns.

Princess Caroline's Battery, circa 1890 with two newly intalled 64 pounder RML guns.

In 1898, a proposal was made to mount two 12-pounder quick-firing guns to cover the waters north of the Bay. Although a suitable site was identified about 30 yards down Willis’s Road, the plan was rejected. Instead, a 6-inch Mark VI gun was proposed in a casemate, later revised in 1902 to a 6-inch Mark VII gun mounted on a central pivot in a barbette emplacement. The existing 64-pounders were removed in August 1904 to make way for the new gun, which was installed and ready for action by July 1905.

Plan of 1905 showing the 6-inch BL Mark VII gun emplacement.

The 6 inch gun on top of the magazine at Princess Caroline's Battery.

The battery remained operational well into the 20th century. The 6-inch gun was fired on the 3^rd December 1915 following reports of submarine activity in the bay. It was manned again in July 1936 during the Spanish Civil War, and in August 1939 it was placed on standby for landward defence, though it retained a seaward firing capability. Two 2-inch projectors were added in October and November 1942. During the Second World War, there were plans to relocate the gun into a rock casemate at Jock’s Balcony for better protection, but this was never carried out. The gun was finally dismantled in 1955 and sold for scrap.

Today the 6-inch gun emplacement and casemates remain a popular tourist attraction for its breathtaking views of the Spanish hinterland. The casemates now form part of the Military Heritage Centre. The centre houses relics that date from the eighteenth century to present day, including weapons, shells, and other artefacts.

64-pdr 58 cwt RML at Princess Caroline's Battery, circa 1961.

War memorial Gibraltar Military Heritage Centre.