Well before 3rd Battalion, Royal Australian Regiment, (3RAR) arrived in Korea in September 1950, other Australians were already involved in the war.
Peacekeepers
Two Australian officers were in Korea when the war began.
In March 1950, 3 months before North Korea invaded South Korea, the United Nations Commission on Korea (UNCOK) asked for military observers because of the tense situation on the Korean border. Australia was a member of UNCOK and sent Major Stuart Peach, who had been a prisoner of the Japanese, and Squadron Leader Ronald Rankin, who had served in the RAAF during World War II.
For 2 weeks before the invasion, Peach and Rankin toured the 38th parallel and submitted a report that the South Koreans were in defensive positions but the North Koreans seemed to be offensively deployed. The Peach-Rankin report became important when North Korea falsely claimed that the south had begun the war by invading the north.
Royal Australian Air Force
The next Australians to arrive were from No. 77 Squadron RAAF. They flew P-51D Mustangs from their base in western Japan.
On 2 July 1950, one week into the war, 77 Squadron was the first United Nations (UN) force to participate after that of the United States.
Part of the Squadron escorted American B-26 Marauders on a bombing mission while the rest escorted transport aircraft flying wounded from Korea to Japan.
Within 5 days, 77 Squadron lost the first of 41 of its personnel to be killed during the Korean War. Squadron Leader Graham Strout failed to pull out of a dive when attacking Samchok railway station on Korea's east coast.
Pilot James Hilary 'Jim' Flemming of No 77 Squadron RAAF standing on the wing of a P-51 Mustang aircraft (A68-757). Photographed in Iwakuni, Japan, on 6 July 1950. Jim flew this aircraft for 3 years before the Korean War and also on the first operational mission flown by 77 Squadron over North Korea. AWM P03595.001
Flight Lieutenant John Irwin Adams DFC of No 77 Squadron RAAF (left) standing on the wing of a P-51 Mustang aircraft while 2 members of the groundcrew prepare for the squadron's first mission over North Korea. Photographed in Iwakuni, Japan, in July 1950. AWM HOBJ0990
Royal Australian Navy
On 29 June 1950, Prime Minister Sir Robert Menzies offered the UN the support of the destroyer HMAS Bataan and the frigate HMAS Shoalhaven, then in Japanese waters serving with the British Commonwealth Occupation Force.
Bataan began convoy escort duty in the Korea Strait on 6 July. The next day, Shoalhaven joined the UN naval force blockading the west coast of Korea.
On 1 August, Bataan, now also on the west coast, fired the Royal Australian Navy's first shots of the war when it exchanged fire with a North Korean coastal battery.
Tribal-class destroyer HMAS Bataan was in Asian waters when the Korean War started on 25 June 1950. On 6 July 1950, Bataan transferred to the United States' Task Group 96.1 for convoy escort duties in the Korean Straits. AWM 300378