The Battle class were a class of destroyers of the British Royal Navy (RN) and Royal Australian Navy (RAN), named after naval or other battles fought by British or English forces. Built in three groups, the first group were ordered under the 1942 naval estimates. A modified second and third group, together with two ships of an extended design were planned for the 1943 and 1944 estimates. Most of these ships were cancelled when it became apparent that the war was being won and the ships would not be required, although two ships of the third group, ordered for the RAN, were not cancelled and were subsequently completed in Australia.

Seven Battles were commissioned before the end of World War II, but only Barfleur saw action, with the British Pacific Fleet.

The first years of World War II had shown that British destroyers were ill-equipped to deal with concentrated air attacks, and the Royal Navy suffered heavy losses as a result. In 1941 urgent consideration of the problem led to a naval staff requirement for a new class of large fleet destroyer with High Angle (HA) twin guns and an HA control system. It was decided that this main armament would be set forward in a superfiring configuration for all guns to engage one target. Arcs of fire were increased by setting the bridge structure further aft than normal. The proposed anti-aircraft (AA) armament were eight 40/60 mm guns in twin mountings set atop the middle and after deck houses to give all around, overlapping arcs of fire. These were to be supplemented by 20 mm guns positioned variously around the ship. Eight 21-inch (533 mm) torpedo tubes were to be carried in two quadruple mounts. A/S armament called for two depth charge rails and four depth charge throwers to be fitted. A new feature was the first use of stabilisers in a destroyer, providing a steadier platform for AA gunnery.

With these parameters accepted, a sketch design was approved in the autumn of 1941 and orders for sixteen ships (two flotillas) were placed under the 1942 programme. Considerably larger than the standard fleet destroyer, these ships were seen as a replacement for the Tribal class which had already suffered many losses. With a length of 379 feet (116 m) they were two feet longer than the Tribals and with a beam of 40 feet 3 inches (12.27 m) were just over three feet wider. It was decided to abandon the usual alphabetical naming of destroyer flotillas and name these ships after famous land and sea battles, thus these ships became known as the 1942 Battle class.

The first ten ships were ordered on 27 April 1942. These comprised Barfleur, Trafalgar and St Kitts (with Swan Hunter, Wallsend); Armada, Solebay and Saintes (with Hawthorn Leslie); Camperdown and Finisterre (with Fairfield, Govan); and Hogue and Lagos (with White, Cowes).

The remaining six ships were ordered on 12 August 1942. These comprised Gabbard (with Swan Hunter); Gravelines and Sluys (with Cammell Laird); and Cadiz, St James and Vigo (with Fairfield, Govan). The order for Hogue and Lagos was moved from Whites to Cammell Laird on the same date.

The placing of orders did not stop design work but by this time plans were too far advanced for big changes to be considered, although some design changes were made to the armament. One change, incorporated with protection against air-attack in mind, was the decision to standardise on the 4.5-inch gun for the main armament rather than the low angle 4.7 inch that was the usual destroyer gun and only effective against surface targets. The four 4.5 inch guns, fitted in two Mk IV turrets, were capable of high angle fire against aircraft and were controlled from a Director Control Tower (DCT) fitted with radar. Another alteration made whilst building was the fitting of a 4-inch gun on a gundeck abaft the funnel. It was also decided that the twin 40/60 mm guns would be fitted on Hazemeyer Mark IV mountings fitted with Radar Type 282. These would be mounted side by side on the middle gundeck between the torpedo tubes and en-echelon atop the after deckhouse. Due to delays in completion, the plans for 20 mm guns were altered and eventually four single 40/60 mm guns in Mk VII mountings were fitted, one forward of the bridge structure behind 'B' gun, one on either bridge wing and one aft on the quarterdeck.

Experience in the Pacific, against the Japanese, pointed to the limited usefulness of the 4 inch gun abaft the funnel and only the first ships completed, Barfleur, Armada, Trafalgar, Camperdown, Hogue and Lagos were fitted with the gun. In all other ships the gun was replaced by two single 40/60 mm Mk VII giving a total of 14 Bofors, the heaviest light AA armament of any British destroyer and heavier than that carried in many cruisers. In time, all the ships fitted with the 4 inch gun had them removed and replaced with the two single 40/60 mm Mk VII Bofors