King’s Bastion is believed to have developed from an earlier Moorish gate which became the Spanish Plataforma de San Lorenzo. In 1773 the British started to build the King’s Bastion as a key point on the western defences of the City, overlooking the harbour.
It was shaped like an arrowhead, with casemated accommodation for 800 men, and flanking batteries as well as the main battery facing out over the water. In 1782 it was a key point of the defence helping destroy the French floating batteries with red hot shot.
In 1859 returns show that King’s Bastion mounted:
- seventeen 32-pdr SB
- six 8-inch SB gun
- two 10-inch howitzers
In 1874 the west end of the bastion was remodelled to mount five muzzle-loading rifles (RMLs) in casemates with armoured shields. There was one heavy 12.5-inch gun in the centre with its’ own semi-circular armoured shield with two loopholes. This was like Zoca Flank and Princess Alexandra Battery. The guns were operational by 1878 and remained in use until 1902.
The casemates in the Bastion were adapted to be used for cold storage and in 1896 the site was used for first electric power station.
During World War 2 a battery 3.7-ins Anti-Aircraft guns were mounted on the gorge of the bastion, and original RML gun embrasures were filled with cement to convert them into loopholes for small arms. The area is now a leisure centre.
For a period after World War 2 the roof of the bastion was used as a saluting battery.
Built about 1857, the Officer’s Mess lies directly opposite King’s Bastion. The proposed plans dated 25th July 1857 call this “New Mess Establishment, Retrenchment King’s Bastion”. The building is still used as a private club.