The King George V-class battleships''' were the most modern British battleships in commission during the Second World War. Five ships of this class were built: HMS King George V (commissioned 1940), HMS Prince of Wales (1941), HMS Duke of York (1941), HMS Anson (1942) and HMS Howe (1942). The names honoured King George V, and his sons, Edward VIII, who had been Prince of Wales, and George VI who was Duke of York before ascending to the throne; the final two ships of the class were named after prominent 18th century admirals of the Royal Navy.

The Washington Naval Treaty of 1922 limited all of the number, displacement, and armament of warships built following its ratification, and this was extended by the First London Naval Treaty but these treaties were due to expire in 1936. With increased tension between Britain, the United States, Japan, France and Italy, it was supposed by the designers of these battleships that the treaty might not be renewed and the ships of the King George V class were designed with this possibility in mind.

All five ships saw combat during World War II, with King George V and Prince of Wales being involved in the action on 24 May to 27 May 1941 that resulted in the German battleship being sunk. Following this, on 25 October 1941, Prince of Wales was sent to Singapore, arriving on 2 December and becoming the flagship of Force Z. On 10 December, Prince of Wales was attacked by Japanese bombers and sank with the loss of 327 of its men. In the aftermath of the sinking, King George V, Duke of York, Howe and Anson provided escort duty to convoys bound for the Soviet Union. On 1 May 1942, King George V collided with the destroyer HMS Punjabi, resulting in King George V being sent to Gladstone docks for repairs on 9 May, before returning to escort duty on 1 July 1942; Punjabi was sunk with 49 dead. In October 1942 Duke of York was sent to Gibraltar as the new flagship of Force H and supported the Allied landings in North Africa in November. Anson and Howe would also provide cover for multiple convoys bound for the Soviet Union from late 1942 until 1 March 1943, when Howe provided convoy cover for the last time. In May 1943 King George V and Howe were moved to Gibraltar in preparation for Operation Husky. The two ships bombarded Trapani naval base and Favignana on 11–12 July and also provided cover for Operation Avalanche on 7 to 14 September. During this time, Duke of York and Anson participated in Operation Gearbox, which was designed to draw attention away from Operation Husky. Duke of York was also instrumental in sinking the German battleship on 26 December 1943. This battle was also the last time that British and German capital ships fought each other.

In late March 1945, King George V and Howe were sent to the Pacific with other Royal Navy vessels as a separate group to function with the US Navy's Task Force 57. On 4 May 1945, King George V and Howe led a forty-five-minute bombardment of Japanese air facilities in the Ryukyu Islands. King George V fired her guns in anger for the last time in a night bombardment of Hamamatsu on 29 and 30 July 1945. Duke of York and Anson were also dispatched to the Pacific, but arrived too late to participate in hostilities. On 15 August Duke of York and Anson accepted the surrender of Japanese forces occupying Hong Kong and, along with King George V, were present for the official Japanese surrender in Tokyo Bay. Following the end of World War II, the ships were phased out of service and by 1957 all of the ships had been sold off for scrap, a process that was completed by 1958.

Design and description Design of the King George V class began in 1928. Under the terms of the Washington Naval Treaty of 1922, a "holiday" from building capital ships was in force until 1931. The battleships of the British Navy consisted of only those old battleships that had been kept after the end of the First World War, plus the two new, albeit slow, s. In 1928, the Royal Navy started considering the requirements for the warships that it expected to start building in 1931.Brown 2000, p. 25

The First London Naval Treaty of 1930 extended the "shipbuilding holiday" to 1937. Planning began again in 1935, drawing on previous work. The new class would be built up to the Treaty maximum displacement of . Alternatives with 16-inch (406 mm), 15-inch (381 mm), and 14-inch (356 mm) main guns were considered and the 15-inch (381 mm) armament was chosen. Most designs were intended to steam at with full power, and it was decided that the likely decisive range in a battle would be from . Armour and torpedo protection formed a much greater portion of the design than that of the previous Royal Navy battleships.Brown 2000, pp. 28–29

In October 1935, the decision was made to use 14-inch (356 mm) guns. The United Kingdom was negotiating for a continuation of the Naval Treaties with the other parties of the London Treaty. The British Government favoured a reduction in the maximum calibre of battleship gun to 14-inch (356 mm) and in early October, the government learned that the United States would support this position if the Japanese could also be persuaded to do so. Since the large naval guns needed to be ordered by the end of the year, the British Admiralty decided on these guns for the King George V class. The Second London Naval Treaty, a result of the Second London Naval Conference begun in December 1935, was signed in March 1936 by the United States, France and Britain and this set a main battery of 14-inch (356 mm) naval guns as the limit.Raven & Roberts, p. 275

Propulsion The King George Vs were the first British battleships to alternate engine rooms and boilers in the machinery spaces, which reduced the likelihood of one hit causing the loss of all power.Brown 2000, pp. 164–165 The machinery was arranged in four engine (turbine) rooms and four boiler rooms, with the eight machinery compartments alternating in pairs of engine or boiler rooms. Each pair of boiler rooms formed a unit with a pair of engine rooms. Nominal full power was with steam at .Journal of Naval Engineering The machinery was designed to operate at an overload power of and Prince of Wales "...main machinery steamed at overload powers of with no difficulties..." during the hunt for the Bismarck.Garzke & Dulin, p. 206 The Admiralty 3-drum boilers operated very efficiently, and similar boilers of nearly identical power, fitted to the older battleship during her rebuilding in 1937 achieved a full-power specific fuel consumption of 0.748 lb per shp on trials which compared favourably with contemporary battleships.Raven, p. 34Garzke & Dulin, p. 66. The achieved 0.753 lb/hr and 0.816 lb/hr on her preliminary and full-power trials, respectively, in 1936. During her full-power trials on 10 December 1940, King George V at displacement achieved with at 230 rpm and a specific fuel consumption of 0.715 lb per shp.Brown 1995, p. 28King George V had her paravanes streamed during her full power trials, which caused an estimated .7 knot loss of speed.Friedman 2015, p.313 The Duke of York at her trials, on 1 November 1941, displacing (sea slight, wind moderate), attained a speed of at 115 rpm and and at 232 rpm and .Burt (2012), p.402 After 1942 the Royal Navy was forced to use fuel oils with considerably higher viscosity and greater seawater content than these boilers could efficiently use.Gray and Killner, JNE, Volume 2, Book 4, January 1949, Sea Water Contamination of Boiler Fuel Oil – Part II The poor quality of the oil fuel combined with the seawater contamination reduced the efficiency of the steam power plant and increased the maintenance required.JNE, Recent Improvements in Oil-Burning Equipment, Parts I, II, & III. The high seawater content was caused by a number of factors; the King George V class used fuel oil as part of the Side Protection System in the liquid layers of the SPS. As the fuel was consumed, water was allowed to enter the bottom of the layer to maintain its defensive qualities. The low-viscosity fuel used in the early part of the war resisted mixing with seawater, and what seawater contamination did occur was easily removed and Britain's oil tanker fleet was relatively intact. After 1942 tanker losses increased and the demands for more aviation fuel led to a degradation of bunker fuel used in steam-driven naval vessels. This fuel readily absorbed seawater from older oil tankers that had increased propensity for seawater leakage, and from contact with seawater in the SPS system. It was also very much more difficult to remove the seawater once this poorer-quality fuel was contaminated. By 1944 the specific full-power fuel consumption had increased to 0.8 lb per shp, and boiler maintenance was becoming increasingly difficult.JNE, Recent Improvements in Oil-Burning Equipment The Admiralty had been aware of this problem and were designing new types of oil sprayers and burners that could burn fuel oil much more efficiently, and sometime after 1944, Duke of York and Anson were fitted with new, higher-pressure oil sprayers and burners that restored the boilers to full efficiency.JNE, Recent Improvements in Oil-Burning Equipment. Possibly post-war. The same oil sprayers and burners were used in along with other detail improvements so that Vanguard achieved a full-power specific fuel consumption of 0.63 lb per shp while using the same steam pressures and temperatures as used on the King George V class.Raven & Roberts, p. 339Garzke & Dulin, pp. 236–297

Protection

The armour protection of the King George V-class battleships was designed after consideration of the Royal Navy's experience of the First World War and upon testing between the wars.Raven & Roberts, p. 263 The design of this class was dominated by the provision of protection.Brown 2000, p. 29 Magazine protection was given priority with a thick belt and deck armour and by placing the magazines at the lowest levels of the ship.Raven & Roberts, p. 285

The horizontal protection over the magazines consisted of three layers with a total thickness of ; the weather deck consisted of of Ducol (D) steel, the main armoured deck was of non-cemented steel armour thick over a D steel deck and above the shell rooms there was another 1.5-inch splinter deck.Okun, Nathan. Armor protection of the battleship KM Bismarck.Raven & Roberts, p. 284 The powder magazines were below the shell rooms for added protection, a practice that was begun with the Nelson-class battleships. The weather deck thickness was the same over the machinery spaces but there the main armoured deck was reduced to over a D steel deck. The main armoured deck was continued forward of the forward armoured bulkhead and gradually reduced from full thickness to , while aft of the after magazines an armoured turtle-back deck covered the steering gear with of armour whilst also providing protection along the waterline.