|Princess Anneís Battery is on the hillside above the harbor. The site is sometime referred to as Princess Carolineís Battery, Princess Ameliaís Battery, or even Princess Royalís Battery. These three battery names, however, refer to 18th and 19th-century batteries located in and around Princess Anneís Battery. Princess Anneís Battery was constructed in 1732 to mount five 12 pounders, and saw action during the Great Siege. During the 19th century, Princess Anneís Battery was rebuilt to house four 12 pounders and three 13-inch mortars.|
In 1942 it was proposed to increase the antiaircraft defense of Gibraltar by mounting seven 5.25-inch guns, three on Europa Point and four at Princess Anneís Battery. The 5.25 QF Mk Is were dual-purpose guns, built for twin mounts on Royal Navy cruisers and battleships. The British Army took the basic design and upgraded it into the Mk II, with a stronger breech ring to allow a muzzle velocity of 2850 f/s as opposed to the Mk Iís 2672 f/s.
The four 5.25 QF Mk II guns on IB mountings did not become operational until 1956. Shortly after becoming operational, the four guns were reduced to caretaker status and declared surplus in the 1990s. The guns could fire ten, 88-pound shells per minute skyward to 55,000 feet, or horizontally to 27,000 yards or 13.5 miles. The Mk IB mounting has an enclosed gun shield, while the shield for the IA mount was open in the rear. The four guns of Princess Anneís Battery are each partially enclosed by a concrete wall. Guns Nos. 1, 2, and 3 have a semisunken magazine, while gun No. 4ís magazine is completely below ground level. To the rear of Gun No. 2 is an entrance into Willisí Gallery, a segment of Gibraltarís 30 miles of underground tunnels.
Princess Anneís Battery was named after the eldest daughter of George II, Princess Anne, Princess Royal of Great Britain and Ireland. She is better known as Princess Anne of Orange due to her marriage to Prince Willem IV of Orange-Nassau.