Pushing east from the positions previously captured by the US troops earlier in the year, after landing at Jacquinot Bay on the southern coast in November, the Australians began advancing across the island towards the Gazelle Peninsula, where they sought to isolate the numerically superior Japanese garrison.

The Japanese had captured the island of New Britain in February 1942 after overwhelming the small Australian garrison stationed around Rabaul.

[1] The Japanese subsequently built up a large garrison on the island, consisting of around 93,000 men from General Hitoshi Imamura's Eighth Area Army.

[3] After this the US 40th Infantry Division had taken over and fighting on New Britain devolved largely into what Gavin Long, the Australian official historian, called a "tacit truce" with the US forces concentrating on defending their airfields on the west of the island – with the 40th Infantry Division concentrated largely around Cape Gloucester[4] – and the Japanese on the eastern side being separated by a "no man's land", in which Australian-led indigenous troops from the Allied Intelligence Bureau (AIB) conducted a small scale guerilla campaign.

[8][9] These forces were bolstered in early January with the arrival of the remaining two companies of the 14th/32nd, along with a troop of artillery from the 2/14th Field Regiment.

[10] Between late January and early February 1945, the Australian 6th Infantry Brigade advanced eastwards along the southern coast of New Britain towards Milim, where they established a patrol base with the intention of fanning out towards Henry Reid Bay.

Elements of the 2/14th Field Regiment established themselves at Karlai Plantation from where they fired support missions across the bay towards Waitavalo.

In early March, the Australian high command ordered an advance towards the coconut plantations at Waitavolo and Tol on the northern edge of Henry Reid Bay.

[5][8] These hills were named "Lone Tree", "Bacon", "Cake", "Young", "Perry's", "Kath's" and "Moose",[13] and were defended by a series of pillboxes, supported by mortars and machine guns.

Japanese planes appeared for the first, and only time, in the campaign in mid-March, with two aircraft dropping several bombs on the bridge over the Wulwut, causing a number of casualties.

[9] Australian operations on the island were constrained by shortages of shipping and air support as these resources were redirected largely to efforts to secure Borneo; these shortages delayed the concentration of the 5th Division considerably and it was not until April that the 5th Division had completed its movements, with the arrival of the 4th and 13th Infantry Brigades being followed by the 2/2nd Commando Squadron.

[18] At the conclusion of hostilities, Australian planners discovered the error that they had made in estimating the size of the Japanese force.