The military history of the United Kingdom in World War II covers the Second World War against the Axis powers, starting on 3 September 1939 with the declaration of war by the United Kingdom and France, followed by the UK's Dominions and Crown colonies, on Nazi Germany in response to the invasion of Poland by Germany. There was little, however, the Anglo-French alliance could do or did do to help Poland. The Phoney War culminated in April 1940 with the German invasion of Denmark and Norway. Winston Churchill became prime minister and head of a coalition government in May 1940. The defeat of other European countries followed – Belgium, the Netherlands, Luxembourg and France – alongside the British Expeditionary Force which led to the Dunkirk evacuation.
I Corps is a corps of the United States Army headquartered in Joint Base Lewis-McChord, Washington. It is a major formation of United States Army Pacific (USARPAC) and its current mission involves administrative oversight of Army units in the Asia-Pacific region, including the Pacific Pathways program.
Operation Downfall was the proposed Allied plan for the invasion of the Japanese home islands near the end of World War II. The planned operation was canceled when Japan surrendered following the atomic bombings of Hiroshima and Nagasaki, the Soviet declaration of war, and the invasion of Manchuria. The operation had two parts: Operation Olympic and Operation Coronet. Set to begin in November 1945, Operation Olympic was intended to capture the southern third of the southernmost main Japanese island, Kyūshū, with the recently captured island of Okinawa to be used as a staging area. In early 1946 would come Operation Coronet, the planned invasion of the Kantō Plain, near Tokyo, on the main Japanese island of Honshu. Airbases on Kyūshū captured in Operation Olympic would allow land-based air support for Operation Coronet. If Downfall had taken place, it would have been the largest amphibious operation in history, surpassing D-Day.
The Allied invasion of Sicily, also known as Operation Husky, was a major campaign of World War II in which the Allied forces invaded the island of Sicily in July 1943 and took it from the Axis powers. It began with a large amphibious and airborne operation, followed by a six-week land campaign, and initiated the Italian campaign.
Operation Cartwheel (1943–1944) was a major military operation for the Allies in the Pacific theatre of World War II. Cartwheel was an operation aimed at neutralising the major Japanese base at Rabaul. The operation was directed by the Supreme Allied Commander in the South West Pacific Area (SWPA), General Douglas MacArthur, whose forces had advanced along the northeast coast of New Guinea and occupied nearby islands. Allied forces from the South Pacific Area, under Admiral William Halsey, advanced through the Solomon Islands toward Bougainville. The Allied forces involved were from Australia, the Netherlands, New Zealand, the US and various Pacific Islands.
The 10th Division was a division of the Australian Army, which served briefly during World War II. It was initially formed on 15 April 1942 from the Militia units of the Newcastle Covering Force. However, personnel shortages led to the division being disbanded in August that year.
Field Marshal Sir Thomas Albert Blamey, was an Australian general of the First and Second World Wars, and the only Australian to attain the rank of field marshal.
The units listed to participate in Operation Downfall — the planned Allied invasion of Japan — as planned in August 1945 were:
South West Pacific Area (SWPA) was the name given to the Allied supreme military command in the South West Pacific Theatre of World War II. It was one of four major Allied commands in the Pacific War. SWPA included the Philippines, Borneo, the Dutch East Indies, East Timor, Australia, the Territories of Papua and New Guinea, and the western part of the Solomon Islands. It primarily consisted of United States and Australian forces, although Dutch, Filipino, British and other Allied forces also served in the SWPA.
The Borneo campaign of 1945 or Second Battle of Borneo, was the last major Allied campaign in the South West Pacific Area during World War II to liberate Japanese-held British Borneo and Dutch Borneo. Designated collectively as Operation Oboe, a series of amphibious assaults between 1 May and 21 July were conducted by the Australian I Corps, under Lieutenant-General Leslie Morshead, against Imperial Japanese forces who had been occupying the island since late 1941 – early 1942. The main Japanese formation on the island was the Thirty-Seventh Army under Lieutenant-General Masao Baba, while the naval garrison was commanded by Vice-Admiral Michiaki Kamada. The Australian ground forces were supported by US and other Allied air and naval forces, with the US providing the bulk of the shipping and logistic support necessary to conduct the operation. The campaign was initially planned to involve six stages, but eventually landings were undertaken at four locations: Tarakan, Labuan, North Borneo and Balikpapan. Guerilla operations were also carried out by Dayak tribesmen and small numbers of Allied personnel in the interior of the island. While major combat operations were concluded by mid-July, mopping-up operations continued throughout Borneo until the end of the war in August. Initially intended to secure vital airfields and port facilities to support future operations, preparatory bombardment resulted in heavy damage to the island's infrastructure, including its oil production facilities. As a result, the strategic benefits the Allies gained from the campaign were negligible.
The Bougainville campaign was a series of land and naval battles of the Pacific campaign of World War II between Allied forces and the Empire of Japan, named after the island of Bougainville. It was part of Operation Cartwheel, the Allied grand strategy in the South Pacific. The campaign took place in the Northern Solomons in two phases. The first phase, in which American troops landed and held the perimeter around the beachhead at Torokina, lasted from November 1943 through November 1944.
The Commonwealth of the Philippines was attacked by the Empire of Japan on 8 December 1941, nine hours after the attack on Pearl Harbor. Although it was governed by a semi-independent commonwealth government, the United States of America controlled the Philippines at the time and possessed important military bases there. The combined Filipino-American army was defeated in the Battle of Bataan and the Battle of Corregidor in April 1942, but guerrilla resistance against the Japanese continued throughout the war. Uncaptured Filipino army units, a communist insurgency, and supporting American agents all played a role in the resistance. Due to the huge number of islands, the Japanese never occupied many of the smaller and more minor islands. Japanese control over the countryside and smaller towns were often tenuous at best.
I Corps was an Australian Army corps, one of three that were raised by the Army during World War II. It was the main Australian operational corps for much of the war. Various Australian and other Allied divisions came under its control at different times. In 1940–1942, the corps was based in the Mediterranean and Middle Eastern theatres, and controlled forces in action against the Germans, Italians and later the Vichy French in North Africa, Greece and Syria–Lebanon.
The New Britain campaign was a World War II campaign fought between Allied and Imperial Japanese forces. The campaign was initiated by the Allies in late 1943 as part of a major offensive which aimed to neutralise the important Japanese base at Rabaul, the capital of New Britain, and was conducted in two phases between December 1943 and the end of the war in August 1945.
The Philippines campaign, Battle of the Philippines, Second Philippines campaign, or the Liberation of the Philippines, codenamed Operation Musketeer I, II, and III, was the American, Mexican, Australian and Filipino campaign to defeat and expel the Imperial Japanese forces occupying the Philippines during World War II.
Australia entered World War II on 3 September 1939, following the government's acceptance of the United Kingdom's declaration of war on Nazi Germany. Australia later entered into a state of war with other members of the Axis powers, including the Kingdom of Italy on 11 June 1940, and the Empire of Japan on 9 December 1941. By the end of the war, almost a million Australians had served in the armed forces, whose military units fought primarily in the European theatre, North African campaign, and the South West Pacific theatre. In addition, Australia came under direct attack for the first time in its post-colonial history. Its casualties from enemy action during the war were 27,073 killed and 23,477 wounded. Many more suffered from tropical disease, hunger, and harsh conditions in captivity; of the 21,467 Australian prisoners taken by the Japanese, only 14,000 survived.
The Battle of Morotai, part of the Pacific War, began on 15 September 1944, and continued until the end of the war in August 1945. The fighting started when United States and Australian forces landed on the southwest corner of Morotai, a small island in the Netherlands East Indies (NEI), which the Allies needed as a base to support the liberation of the Philippines later that year. The invading forces greatly outnumbered the island's Japanese defenders and secured their objectives in two weeks. Japanese reinforcements landed on the island between September and November, but lacked the supplies needed to effectively attack the Allied defensive perimeter. Intermittent fighting continued until the end of the war, with the Japanese troops suffering heavy loss of life from disease and starvation.
At the start of 1939, the British Army was, as it traditionally always had been, a small volunteer professional army. At the beginning of the Second World War on 1 September 1939, the British Army was small in comparison with those of its enemies, as it had been at the beginning of the First World War in 1914. It also quickly became evident that the initial structure and manpower of the British Army was woefully unprepared and ill-equipped for a war with multiple enemies on multiple fronts. During the early war years, mainly from 1940 to 1942, the British Army suffered defeat in almost every theatre of war in which it was deployed. But, from late 1942 onwards, starting with the Second Battle of El Alamein, the British Army's fortunes changed and it rarely suffered another defeat.
The Australian Army was the largest service in the Australian military during World War II. Prior to the outbreak of war the Australian Army was split into the small full-time Permanent Military Forces (PMF) and the larger part-time Militia. Following the outbreak of war on the 3rd of September 1939, 11 days later, on 14 September 1939 Prime Minister Robert Menzies announced that 40,000 members of the Militia would be called up for training and a 20,000-strong expeditionary force, designated the Second Australian Imperial Force, would be formed for overseas service. Meanwhile, conscription was introduced in October 1939 to keep the Militia at strength as its members volunteered for the AIF. The Australian Army subsequently made an important contribution to the Allied campaigns in the Mediterranean, the Middle East and North Africa fighting the Germans, Italians and Vichy French during 1940 and 1941, and later in the jungles of the South West Pacific Area fighting the Japanese between late 1941 and 1945. Following the Japanese surrender Australian Army units were deployed as occupation forces across the South West Pacific. Meanwhile, the Army contributed troops to the British Commonwealth Occupation Force (BCOF) in Japan from 1946.
The Philippine Army was established on December 21, 1935, as the Army of the Philippines, with a general headquarters in Manila, and units and formations based throughout the provinces of the Philippines.
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