Madang sits on the Schering Peninsula where it juts into Astrolabe Bay, a sheltered deep-water harbor on Papua New Guinea's north coast. Kranket Island closes the lagoon from the sea. The Adelbert Range hems the town to the north; the Finisterres rise behind it to the south. Before the war, the greater Madang area held roughly 25,000 to 30,000 indigenous people, around 200 Europeans, and fewer than 100 Asian residents. When the Japanese landed in early March 1942 as part of the push to build their great southern base at Rabaul, they turned the harbor into a forward logistics hub and extended it eight miles north to Alexishafen. The Europeans had mostly been evacuated the year before. The town would sit behind Japanese lines for twenty-six months.

The battle for Madang was really the denouement of Shaggy Ridge. Once the Japanese line in the Finisterres broke in late January 1944, the remnants of the 20th Division under Lieutenant General Shigeru Katagiri had no choice but to withdraw toward the coast. Major General Allan Boase's 11th Division relieved George Vasey's exhausted 7th Division, and two battalions of the 15th Brigade, the 57th/60th and 58th/59th, began grinding forward from Kankiryo toward Bogadjim via the Mindjim River. The slopes were rugged and densely forested. The Japanese fought a skilled fighting withdrawal, building outposts in a five-mile arc south of Bogadjim. Australian patrols bypassed them. Intelligence from local people pointed the way to concentrations of enemy troops at Erima Plantation. The Gori and Palpa rivers, swollen with monsoon rain, were the worst obstacles.

While the Australians worked down the mountains, the other half of the pincer moved along the coast. Two battalions of the U.S. 32nd Infantry Division had already come ashore at Yalau Plantation after advancing east from Saidor. They pushed toward Bau Plantation and Yangalum, fighting small skirmishes, looking for the Australians coming the other way. The 532nd Engineer Boat and Shore Regiment helped clear the Rai Coast between Sio and Saidor. In the final act, Australian troops from the 8th Infantry Brigade were shipped up the coast by sea. The Japanese 20th Division, fighting rearguard actions the whole way, kept slipping west. When the converging forces entered Madang on 24 and 25 April 1944, they found it had been abandoned. The Japanese had kept going, toward the Sepik, toward Aitape and Wewak and eventually Hollandia.

The 30th Infantry Battalion led the way along the northern edge of Astrolabe Bay toward the airfield. After the war the Australian Army, which had been generous with battle honours throughout the New Guinea campaign, issued one for "Madang" and gave it to the 30th alone. No other unit received it. The honour marks a peculiar truth about this battle: it was won by walking, not by fighting. The three Japanese divisions that slipped away from Madang were not destroyed. They would dig in further west and take another year to defeat. Still, the Huon Peninsula and the Ramu Valley were now firmly in Allied hands, and Madang's harbour, the old German Friedrich-Wilhelmshafen, would soon shelter a US Navy base at Alexishafen and supply the next advance along the coast.