The ships were designed as armoured frigates in response to an invasion scare sparked by the launch of the French ironclad Gloire and her three sisters in 1858.

The ships spent their first commission with the Channel Fleet before being rearmed with new rifled muzzle-loading guns in the late 1860s.

[1] The naval architect and historian David K. Brown commented, "What made [Warrior] truly novel was the way in which these individual aspects were blended together, making her the biggest and most powerful warship in the world.

[4] This was 44 feet (13.4 m) longer than the Mersey, the longest wooden-hulled ship in the Royal Navy.

The hull was subdivided by watertight transverse bulkheads into 92 compartments and had a double bottom underneath the engine and boiler rooms.

[6] Two bilge keels were fitted (the first used by the Royal Navy), which significantly reduced the roll of the ships.

[8] The Warrior-class ships had one 2-cylinder trunk steam engine made by John Penn and Sons driving a single 24-foot-6-inch (7.5 m) propeller.

[9] Ten rectangular boilers[10] provided steam to the engine at a working pressure of 20 psi (138 kPa; 1 kgf/cm2).

The engine produced a total of 5,267 indicated horsepower (3,928 kW)[11] and was the most powerful thus far built for a warship.

The ships carried 800 long tons (810 t) of coal, enough to steam 2,100 nautical miles (3,900 km; 2,400 mi) at 11 knots (20 km/h; 13 mph).

Firing tests carried out in September 1861 against an armoured target, however, proved that the 110-pounder was inferior to the 68-pounder smoothbore gun in armour penetration and repeated incidents of breech explosions during the Battles for Shimonoseki and the Bombardment of Kagoshima in 1863–1864 forestalled plans to completely equip the ships with the 110-pounder gun.

The shell of the 40-pounder breech-loading gun was 4.75 inches (121 mm) in diameter and weighed 40 pounds (18.1 kg).

[19] The Warrior-class ships had a wrought-iron armour belt, 4.5 inches (114 mm) thick, that covered 213 feet (64.9 m) amidships.

[12] The gun ports of the Warrior-class ships were built 46 inches (1.2 m) wide, which allowed the 68-pounders to traverse 52°.

[5] HMS Warrior joined the Channel Fleet in July 1862 and was placed in ordinary from 1864 to 1867, during which time she was refitted.

The ship rejoined the Channel Fleet in 1867 and towed a floating drydock to Bermuda in 1869 with her sister Black Prince.

Black Prince was placed in reserve in 1878 in Devonport until she was converted to a training ship in 1896 in Queenstown, Ireland and renamed Emerald in 1903.