MAX BLENKIN | AAP Defence Correspondent
Australian War Memorial historian Karl James says some 1,200 Australians died in this slow grinding campaign that was instrumental in recovering great areas of New Guinea from the Japanese.
Dr James said it was the largest ever offensive by Australian forces, involving five divisions plus significant RAAF and Australian navy forces.
The Australian losses were comparatively low, compared with the earlier fighting, he said.
That was because of the army's professionalism and mastery of jungle warfare, and the allies' advantages in weaponry and logistics against the increasingly desperate Japanese.
"The dark days of 1942 when Australian units were deployed piecemeal to Papua with minimal preparation and equipment were over," he said.
Japanese losses amounted to some 35,000.
Hard-fought battles occurred at locations such as Bobdubi Ridge, Komiautum, Finschhafen, Kaiaipit and Shaggy Ridge, events overshadowed by the earlier Kokoda battles.
There were large scale airborne and amphibious landings, daring small-scale commando raids and ceaseless jungle patrols.
There was also great heroism, with four Victoria Crosses awarded to Australian soldiers after these battles.
Some, like Corporal Leslie "Bull" Allen, who rescued 12 wounded American soldiers under Japanese fire in fighting on Mount Tambu, missed out.
He was among 134 Australian servicemen nominated for a retrospective VC in a recent inquiry into unresolved recognition for past acts of gallantry.