When Britain declared war on Imperial Germany on 4 August 1914, Australia was automatically at war too. Prime Minister Joseph Cook put it plainly the next day: when the Empire is at war, so also is Australia. Within hours, the British Admiralty was worried about one thing. Count Maximilian von Spee's East Asia Squadron, with the cruisers SMS Scharnhorst and SMS Gneisenau, was loose somewhere in the Pacific. As long as its chain of German wireless stations, from Yap in the Carolines to Rabaul in New Britain, could feed it intelligence, the squadron could prey on Allied shipping. Silence the stations, and you blinded the fleet. That assignment fell to a force that did not yet exist.

The Australian Naval and Military Expeditionary Force was thrown together in eleven days. Recruiting opened in Sydney on 11 August 1914, and by the time the transport HMAS Berrima sailed on 19 August, it carried a thousand newly enlisted infantrymen, 500 naval reservists pressed into service as infantry, and a handful of machine gun crews. Most had never been in uniform before. The defenders of German New Guinea numbered just 61 German officers and NCOs, mostly reservists far past their fighting years, backed by roughly 240 Melanesian police, half-trained. The radio station at Bita Paka was held by eight Germans and sixty Melanesian police under Captain Hans Wuchert, with orders to destroy the mast before retreating. A detachment at nearby Toma was dug in under Lieutenant Robert von Blumenthal, who had acquired the nickname Lord Bob.

The Australians landed at Kabakaul and nearby Herbertshohe at dawn on 11 September 1914 and raised the Union Jack at 07:00. Lieutenant Rowland Bowen led two officers and 25 naval reservists up the dirt road toward Bita Paka, seven kilometres inland. By 09:00 they had pushed two thousand yards into dense scrub. That was when the ambushes began. A group of twenty Melanesian soldiers, led by three German reservists, opened fire from the treeline. Snipers waited in the tops of kapok trees. The Australians uncovered and defused a pipe mine buried under the track, wired to a firing key hidden in a lookout tree. At a trench across the road, a half-battalion reinforcement under Lieutenant Commander Charles Elwell launched a bayonet charge. Elwell died at the head of it, his sword drawn. By 19:00 the Australians reached the radio station. It was empty. The mast had already come down.

Seven Australians were killed at Bita Paka and five wounded. One German NCO died, one was wounded, and nineteen Germans were captured. Among the Melanesian police who had been drafted into defending a colonial power that was not their own, about thirty were killed, ten were wounded, and fifty-six captured. Later, persistent allegations emerged that some of the Melanesian losses came from Australians bayoneting prisoners. No one was ever charged. Three days after the battle, the submarine HMAS AE1 vanished on patrol off Rabaul with all thirty-five men aboard. Her wreck would not be found until 2017. In the balance sheet of a war that would eventually kill 60,000 Australians, these numbers were almost invisible. In the small world of New Britain in September 1914, they were catastrophic.

The surviving German defenders retreated nineteen miles inland to Toma, where Governor Eduard Haber hoped to hold out until von Spee's squadron arrived. Von Spee never came. A 200-strong Australian detachment with a single 12-pounder gun bluffed Haber into surrender on 17 September. Nearly all of German New Guinea passed to Australian control. Later, Australians admitted to looting German civilian property during the occupation, and soldiers were court-martialled. What did not change was life for the Melanesians. Australian military administration continued the German policies of indentured labour on copra plantations, the native head tax, and official floggings. The colony became the Territory of New Guinea under League of Nations mandate in 1921, and stayed under Australian administration until Papua New Guinea's independence in 1975.

Many of the Australians who fought at Bita Paka re-enlisted in the Australian Imperial Force after the campaign. They were at Gallipoli by April 1915. Colonel William Holmes, who had commanded at Bita Paka, was killed on the Western Front in 1917. The battle never earned a chapter in the national memory the way Gallipoli did. A war for a radio station on the far side of the world did not match the scale of industrial warfare that swallowed the next four years. Yet the cemetery at Bita Paka still holds the graves of those seven Australians, including Billy Williams and Brian Pockley, who died before most of their countrymen knew there was a war to die in.