While the UK had accommodated the main rear base for the First Australian Imperial Force during most of World War I, the deployment during 1940 was the only time significant numbers of Australian combat soldiers were based in the country during World War II. These soldiers arrived in mid-June on a convoy which had been diverted from its original destination in the Middle East. During the Battle of Britain the Australian force formed part of the mobile reserve which would have counter-attacked any German amphibious or airborne landings in southern England. The Australians were moved to eastern England in October 1940 before departing the country in several convoys between mid-November 1940 and January 1941 in order to concentrate the AIF in the Middle East.
In mid-1944 AIF personnel were dispatched to the UK to establish facilities to accommodate and support the thousands of Australian POWs held by Germany once they were released. Significant numbers of released AIF POWs arrived in the UK as the war in Europe neared its conclusion during April 1945 and ended in May. After being granted a period of leave, these men were accommodated at reception camps located in and around the coastal town of Eastbourne until they could be repatriated to Australia. Almost all of the released prisoners had departed the UK by August 1945.
At the time of the two world wars Australia and the United Kingdom (UK) had a very close relationship. Australia was a self-governing dominion within the British Empire, with its foreign and defence policies being strongly influenced by those of the British Government. Most Australians were either descended from Britons or had been born in the UK, leading to a widespread perception that Britain was the "Mother Country".
The UK accommodated the rear base for the First Australian Imperial Force for most of World War I. From 1916 until the end of the war in 1918 the majority of AIF fought on the Western Front in France. The force's administrative headquarters was in London, and large numbers of Australian training, medical and other support facilities were located in the UK. In addition, Australian soldiers frequently took leave in the country. As a result, virtually all members of the AIF who served in France passed through the UK. Historian Roger Beckett has written that "from summer 1916 to the end of the war there were never fewer than 50,000 Australian troops in Britain". Following the end of the war all AIF personnel in France were gradually transferred to the UK, from where they embarked on ships bound for Australia. In May 1919 the remaining elements of the AIF in France were moved to the UK, leading to the number of Australians there peaking at 70,000. By the end of 1919 almost all AIF personnel had departed the UK, and the force was formally disbanded on 1 April 1921.
Following the outbreak of World War II, the Australian Government established a Second Australian Imperial Force on 15 September 1939. Volunteers for the AIF were liable for service in Australia or overseas. Four AIF infantry divisions were eventually established, with three being deployed to the Middle East and one to Malaya between 1940 and 1941. More than 10,000 Royal Australian Air Force (RAAF) airmen trained under the Empire Air Training Scheme and several RAAF flying squadrons served in the UK during the war. A small number of Royal Australian Navy warships operated from the UK at various times between 1940 and 1942, and hundreds of Australians who had been posted to the Royal Navy were based in the country.