Hurst Castle was built between 1861 and 1870 at the sire of an earlier Tudor coastal defence position. The long line of gun emplacements were granite casemates with iron shields covering the narrow channel between Hurst Castle and Fort Albert. There were a total of 61 gun 9-inch RML gun emplacements, 37 guns on the West and 24 on the East face. There were also plans for three turrets on the roof, each mounting two guns, but none of these were ever built.
Twenty one 9-inch RML guns were fitted by 1873. As the armour on naval vessel improved, heavier guns were needed to interdict them thus leading to a need to improve the effectiveness of the coastal artillery. By 1879 the armament mounted in Fort Hurst was: