The Royal Navy during the Second World War played a crucial role in the Allied victory. Its main tasks included the protection of merchant ships in the Atlantic against German U-boats and the defence of British territories but the conflict exposed its vulnerabilities and marked a turning point in naval history.
Facing early setbacks and defeat, including the loss of capital ships, the Royal Navy struggled with new threats such as powerful German U-boats, Italian and Japanese surface raiders, and devastating naval air power.
Throughout the war, the Navy encountered persistent problems in protecting convoys from submarine attacks and adapting to rapidly evolving naval technology. Its greatest successes included the victory over the Italians in the Battle of Cape Matapan, the naval battle off the North Cape and the evacuation of the British Expeditionary Force from Dunkirk.
The war catalyzed significant technical developments, most notably the emergence of the aircraft carrier as the dominant warship, eclipsing the battleship's long-held supremacy in fleet operations. By the end of the war, the immense expansion of the United States Navy had overtaken the Royal Navy’s position as the world’s most powerful maritime force, signaling a shift in global naval dominance.
Background At the beginning of the Second World War, the Royal Navy was the strongest navy in the world. It had 20 battleships and battlecruisers ready for service or under construction, twelve aircraft carriers, over 90 light and heavy cruisers, 70 submarines, over 100 destroyers as well as numerous escort ships, minelayers, minesweepers and 232 aircraft. However, the British were faced with the strategic problem of protecting their huge empire. At least at the start of the war, there was no comprehensive strategy, as British naval objectives were the same as they had been since the battle against Napoleon - to keep open global transport and communication routes by establishing and maintaining naval supremacy in the North Sea, Atlantic and Mediterranean. In return, the Kriegsmarine initially had two battleships, two obsolete pre-dreadnoughts, three pocket battleships, two heavy cruisers, six light cruisers, 61 U-boats, 21 destroyers and 42 other ships such as minesweepers, torpedoes and speedboats at its disposal.
History 1939
On 3 September at 11:17, seventeen minutes after the British ultimatum to Germany to withdraw from Poland had expired, the Royal Navy entered the war. It set up the blockade of Germany restricting supplies by sea to Germany. In September the aircraft carrier HMS Courageous was sunk while on anti-submarine patrol and in October the battleship HMS Royal Oak was sunk in the protected anchorage of Scapa Flow by a German submarine. The first major battle between the Kriegsmarine and the Royal Navy took place off the coast of South America on 13 December. There, a squadron of three cruisers under the command of Commodore Henry Harwood encountered the heavy cruiser (described as a "pocket battleship") the Admiral Graf Spee. Despite superior firepower - the British ships were all badly damaged - the German ship withdrew to the harbour of Montevideo. After four days, during which the British demanded the internment of the Admiral Graf Spee by Uruguay, believing escape to be impossible the ship was sunk by the Germans.
1940
During the German invasion of Norway, there were battles off Narvik on 10 and 13 April, in which 10 German destroyers (half the German destroyer fleet) was destroyed. On 10 May 1940, the German Wehrmacht began the Western Campaign. Due to the rapid advance, the British Expeditionary Corps was forced to retreat to Dunkirk. On 26 May, Winston Churchill ordered the evacuation of the surrounded troops. In an unprecedented show of strength, the Royal Navy was able to provide over 800 ships rescuing over 300,000 soldiers bring them safely to England by 4 June. In addition to the threat posed by the Kriegsmarine in the Atlantic, the Royal Navy was confronted with a second front in the Mediterranean following Italy's declaration of war on 10 June. The British saw Italy as a second-class military power. But unlike the Royal Navy, the Regia Marina with its six battleships, seven heavy cruisers, twelve light cruisers, 120 destroyers and torpedo boats and 115 submarines was concentrated in the Mediterranean. After the Royal Navy had destroyed the French battleships in Mers-el-Kébir on 3 July as part of Operation Catapult in order to prevent them from falling into German hands, the first battle between the Italians and British took place six days later off Punto Stilo. The battle ended in a draw. Further smaller clashes followed until November, which the British were able to win. During the attack on Taranto on 11 and 12 November, the British were able to deal a heavy blow to the Italian navy. On 27 November, the last major clash of 1940 took place in the naval battle at Cape Teulada; however, it ended without a victor.
1941 At the beginning of 1941, the Royal Navy was confronted with the increasing threat posed by German U-boats. By the beginning of the year, Great Britain had lost almost 4 million tonnes of cargo. The destroyers were too slow and the technology used was not fully developed. The sonar, called Asdic by the British, only had a range of 1,300 metres; bearing and distance could not be read correctly and it was almost impossible to distinguish between submarines and surface units. To intensify the attacks on British merchant ships, the Kriegsmarine launched the Operation Rheinübung in May with the battleship Bismarck and the heavy cruiser Prinz Eugen.
At 05:35 on the morning of 24 May, the German ships were sighted by the battlecruiser Hood and the battleship Prince of Wales. After the distance had been reduced to 23 kilometres, the battle began at 05:52 with the Hood opening fire. However, the Hood initially mistook the Prinz Eugen for the Bismarck. While the British struggled to fire their guns, one of the German ships hit the Hood, causing a rapidly spreading fire amidships. Then, at around 06:00 in the morning, a huge explosion caused the Hood to break in two and sink within minutes. All but three of the 1,418 crew members were killed. The Prince of Wales continued the battle, but was hit several times before breaking off and retreating behind a wall of smoke. As the Bismarck had also taken a hit, damaging some of her fuel tanks, she was tracked down by the British due to leaking oil and eventually sunk, taking most of her crew with her.
In the Mediterranean, the hope that the Italians could be defeated quickly faded. In fact, Italy went on the offensive at the Battle of Cape Matapan, but was defeated by the Royal Navy. For the majority of the year, the Italian forces merely escorted supply convoys. It was not until the end of the year that major fighting resumed with the First Naval Engagement in the Gulf of Syrte, which ended inconclusively. By now, Britain was not only fighting Nazi Germany alone (due to the collapse of the Western Front in May 1940 and the loss of France as an ally), but was also heavily engaged in the Mediterranean and the Middle East, which meant a complete reversal of pre-war strategic priorities, whereby the Mediterranean had to be abandoned if necessary in order to concentrate a large battle fleet and send it to East Asia.
In August 1941, when the dual demands of the Atlantic and the Mediterranean were already severely overstretching the Navy's resources in terms of all types of ships, there was a danger of a Japanese attack on Singapore, the Royal Navy's base in East Asia. On 3 December, even before Japan declared war on 7 December, Britain sent the Prince of Wales and the Repulse to Singapore with their destroyer escort. Their loss on 9 December marked the end of another difficult year for the Royal Navy.
1942
The year 1942 began as the previous had ended. In the Atlantic, the amount of cargo destroyed in the first four months had risen to almost one million tons. To make matters worse, the Royal Navy, now in Ceylon, was confronted with the temporarily most powerful navy in the world after the loss of Singapore at the end of February. Shaken by this severe blow, the War Cabinet hurriedly reinforced the Eastern Fleet so that, by the end of March 1942, it had five battleships, two fleet carriers (Indomitable and Formidable), the older carrier Hermes, seven cruisers, sixteen destroyers and seven submarines. In the Mediterranean, Malta faced an ever-increasing siege. In order to maintain supplies to the island, the British deployed large flotillas to escort convoys to Malta. In March, the Second Sea Battle in the Gulf of Syrte took place, which ended with the defeat of the Axis powers. The British victory was followed by a serious setback in June and August during Operations Vigorous, Harpoon and Pedestal. The year ended with the capture of Madagascar, which strengthened the Royal Navy's position in the Indian Ocean.
1943 In the early days of 1943, the Royal Navy faced a significant challenge in the Atlantic. The fuel crisis and shortage of ships and escorts posed a serious threat to the Navy's operations. Following the extensive decryption of the Enigma with four cylinders in January and the introduction of air-to-ground radar in March, as well as the conversion of convoy protection, the tide began to turn in favour of the British. After the defeat in North Africa in November of the previous year and the conquest of Sicily in July and August, Italy was eliminated as an opponent in the war. Following the conclusion of armistice negotiations in September, Italy joined the Allied forces. Concurrently, the Italian Navy occupied the islands of Milos, Limnos, Chios, Skyros, Rhodes and the majority of Crete. 1944
In the penultimate year of the war, the Royal Navy was on the advance on all fronts. In the Indian Ocean, it was able to decisively weaken and push back the Japanese in several operations by attacking Sumatra and Java. In the Mediterranean, the Royal Navy was able to sink half of all captured Italian torpedo boats by the end of the year. At the same time, it supported the Allied landings in Lazio as part of Operation Shingle. In addition, the Admiralty prepared for the Normandy landings. Neptune was the last operation of global significance to be commanded by the Royal Navy. Of the almost 6,500 ships, 70 per cent were provided by the British. The Royal Navy went on to take part in several operations to liberate France and the Netherlands. 1945 In Europe, the war ended for the Royal Navy with the surrender of the German U-boat fleet by Karl Dönitz on 4 May. Already agreed the previous year, the British Pacific Fleet became part of the US 5th Fleet in the Pacific in March as Task Force 57 and was entrusted with flank defence during Operation Iceberg. From late March to May, it successfully neutralised the Japanese airfields on the Sakishima Islands and Taiwan. In July and August, now as part of the US 3rd Fleet, she strafed Hitachi, Nojima Saki, Shionomisaki, Shimizu, Hamamatsu and Kamaishi. The shelling of a musical instrument factory by the King George V on 29 July ended the Royal Navy's war operations. Aftermath