It decided that they were going to form a fast wing of the battlefleet, which meant that they required heavier armour and armament to fight their counterparts in opposing fleets (thus necessitating larger hulls and higher costs).

In these, his first design, he perpetuated the worst feature of the designs by his predecessor, Sir William White, by placing the secondary armament of six-inch (150 mm) guns in embrasures a deck below the main armament which meant that the guns were inoperable in anything more than a dead calm sea.

[5] They rolled quickly with a metacentric height of 4.2 feet (1.3 m) at deep load and their six-inch guns were as wet as predicted.

[6] The cruisers were powered by two 4-cylinder triple-expansion steam engines, each driving one shaft, which produced a total of 23,000 indicated horsepower (17,150 kW) and gave a maximum speed of 23 knots (43 km/h; 26 mph).

At full capacity, they could steam for 8,130 nautical miles (15,060 km; 9,360 mi) at a speed of 10 knots (19 km/h; 12 mph).

[5] Twenty Vickers quick-firing (QF) 3-pounder guns were fitted for defence against torpedo boats, six on turret roofs and fourteen in the superstructure, all on pivot mounts.

[3] The funnels proved to be too short in service and they were raised about 6 feet (1.8 m) four years after completion to keep the superstructure free of smoke in a following wind.

[16] The ship's foremast was converted to a tripod mast to support the weight of the fire-control director probably added in 1917.

[17] Duke of Edinburgh and Black Prince served in the Channel, Atlantic and Home Fleets before World War I.

They were stationed in the Mediterranean when World War I began[14] and participated in the pursuit of the Goeben and Breslau as part of the 1st Cruiser Squadron, but was ordered not to engage.

[20] The two sisters rejoined the 1st Cruiser Squadron in December 1914, which had transferred to the Grand Fleet and participated in the Battle of Jutland in May 1916.

[19] Black Prince became separated from the fleet when darkness fell and was sunk with all hands by German battleships later that night.

[19] After Jutland Duke of Edinburgh was ordered to reinforce the patrols north of the Shetland Islands against German blockade runners and commerce raiders.