The six-month military campaign conducted in Papua between July 1942 and January 1943 by the Australian army, with help from the United States, saw some of the famous battles of Australian military history. These included the fighting retreat on the Kokoda Trail, the defence at Isurava, the battle at Milne Bay, the counter-offensive over the Kokoda Trail culminating in the victory at Oivi-Gorari and the gruelling battles at Buna, Gona and Sanananda.

Then, seven months later, the Australian army began a series of spectacular military operations in New Guinea. On 4 September 1943 the 9th Australian Division landed from the sea near the town of Lae. Next day the 7th Division began to arrive by air at the captured airstrip at Nadzab, and together the divisions closed in on Lae. Less than a month later the 9th Division carried out another amphibious landing, at Finschhafen, and the battles there ended with the seizure of the Japanese mountain stronghold at Sattelberg. Meanwhile, with the assistance of daring work by Australian commandos and American transport aircraft, the 7th Division advanced up the Markham and into the Ramu Valley. This thrust finished with the successful capture of Shaggy Ridge early in 1944. The campaign was an outstanding orchestration of the land, sea and air forces of two countries.