British Commonwealth Occupation Force (BCOF)
The BCOF force totalled 45,000 personnel from Britain, India, New Zealand, and Australia. Close to 16,000 Australians served in BCOF, including infantry, air force and 130 Australian General Hospital personnel. The Royal Australian Navy also had a presence in the region as part of the British Pacific Fleet.
Their primary objective was to enforce the terms of the unconditional surrender that had ended the Second World War. BCOF was required to maintain military control and supervise the demilitarisation and disposal of the remnants of Japan's war-making capacity. By the end of 1946 the task of demilitarising Japan required less effort and the role of the occupying forces changed. Guard duties and training becoming the main focus. The RAN component of BCOF, with assistance from the RAAF, was responsible for patrolling the Inland Sea, to prevent smuggling and illegal immigration.
At the peak of its involvement the Australian component of BCOF was responsible for over twenty million Japanese citizens and 57,000 square kilometres of country. By the end of 1948, BCOF was composed entirely of Australians. The force was dismantled on 28 April 1952 when the Japanese Peace Treaty came into effect.