The campaign consisted of a series of battles fought between July and November in what was then the Australian Territory of Papua. The Japanese objective was to seize Port Moresby by an overland advance from the north coast, following the Kokoda Track over the mountains of the Owen Stanley Range , as part of a strategy to isolate Australia from the United States.
Japanese forces landed and established beachheads near Gona and Buna on 21 July Opposed by Maroubra Force , then consisting of four platoons of the 39th Battalion and elements of the Papuan Infantry Battalion , they quickly advanced and captured Kokoda and its strategically vital airfield on 29 July.
Despite reinforcement, the Australian forces were continually pushed back. The Japanese advanced to within sight of Port Moresby but withdrew on 26 September. They had outrun their supply line and had been ordered to withdraw in consequence of reverses suffered at Guadalcanal. The Australian pursuit encountered strong opposition from well-prepared positions around Templeton's Crossing and Eora Village from 11 to 28 October.
Following the unopposed recapture of Kokoda, a major battle was fought around Oivi and Gorari from 4 to 11 November, resulting in a victory for the Australians. By 16 November, two brigades of the Australian 7th Division had crossed the Kumusi River at Wairopi , and advanced on the Japanese beachheads in a joint Australian and United States operation.
The Japanese forces at BunaβGona held out until 22 January Australian reinforcement was hampered by the logistical problems of supporting a force in isolated, mountainous, jungle terrain. There were few planes available for aerial resupply, and techniques for it were still primitive. Australian command considered that the Vickers machine gun and medium mortars were too heavy to carry and would be ineffective in the jungle terrain.
