Allied retaking of New Britain

Bombing of Rabaul

Japanese forces invaded and captured Rabaul on 23 January 1942. This was the start of the Japanese invasion of the mandated Australian Territory of New Guinea.

After the fall of Rabaul, Allied forces began a bombing campaign over the town, starting with Catalinas from Nos. 11 and 20 Squadrons RAAF. This became one of the longest-running air campaigns of the Pacific war. It lasted 3.5 years. Allied crews faced Japanese anti-aircraft guns and fighter aircraft. Losses were high.

Operation Cartwheel and Coastwatchers

In 1943, the Allies launched Operation Cartwheel. This aimed to recapture the Japanese base at Rabaul. But in August 1943, Allied commanders decided not to retake Rabaul. Instead, they would isolate and neutralise it.

Before the operation could start, intelligence operatives needed to land on the islands around New Britain. Known as Coastwatchers, they gathered intelligence, warned of air raids, monitored Japanese movements, and sought local support. Most of those who had stayed after the Japanese invasion in 1942 had been killed, captured or evacuated. The new Coastwatcher parties were landed in March and September 1943. They comprised 19 Australians, and 27 Papuans and New Guineans.

Arawe and Cape Gloucester

As part of the wider operation, Allied forces planned to capture Japanese airfields at Cape Gloucester on the western side of New Britain. To distract the Japanese forces, the Allies used several diversions.

On the night of 29 November, five Allied warships arrived off Gasmata. They included the Australian destroyers HMAS Arunta and HMAS Warramunga. The plan was to convince the Japanese that an Allied landing was to take place.

On 15 December 1943, another diversionary landing occurred. US Army and Marine Units, supported by the Australian Landing Ship Infantry (LSI) HMAS Westralia, landed at Arawe, about 100 km south of Cape Gloucester. The Japanese responded by conducting frequent air raids.

The Allies now focused on Cape Gloucester. But they didn't have up-to-date navigation charts of the area. The Australian corvette HMAS Shepparton was tasked with surveying the Dampier Strait. This was very risky, as they had to do it in daylight. The Australians posed as a Japanese ship. They stripped the Shepparton of its Australian markings and lowered its battle ensign. Despite a flyover by a Japanese aeroplane, they successfully completed their mission.

On 25 December 1943, Task Force 74 set sail from Milne Bay for Cape Gloucester. It included the cruisers HMAS Australia and HMAS Shropshire and the destroyers HMAS Arunta and HMAS Warramunga. The diversions had worked. Although the Japanese spotted the convoy, they believed it was carrying reinforcements to Arawe. They launched an air raid there rather than at Cape Gloucester.

At Cape Gloucester, for 80 minutes, Allied ships and aircraft bombarded the shoreline. Then US marines landed. The first wave of Japanese fighter aircraft sank a US destroyer and damaged others. But the Allies shot the second wave down.

After the landing, US aircraft began operating from the Cape Gloucester airfields. In March 1944, they were joined by Kittyhawks from Nos. 80, 78 and 75 Squadrons RAAF. Boomerangs from 'B' Flight of No. 4 Squadron RAAF also arrived to conduct low-level reconnaissance.

Gazelle Peninsula

By August 1944, the remaining 93,000 Japanese were completely isolated on New Britain. Allied warships and aircraft blockaded Rabaul, cutting off most of the Japanese supplies. But Allied commanders worried that the Japanese, under Lieutenant General Hitoshi Imamura, would still be able to fight back.

In August, the Australian 5th Division took over from the US Army 40th Infantry Division garrisons at Arawe and Cape Gloucester.

The US forces had only held a defensive perimeter. But the Australians went on the offensive, advancing up both coasts towards Rabaul. Small Australian guerrilla forces also operated behind enemy lines. Led by Coastwatchers, they recruited and armed the local populace against the Japanese.

The main advance began in October 1944. The Australians' aim was to establish a cordon across the narrowest part of the Gazelle Peninsula, between Wide Bay and Open Bay. By March 1945 they had successfully cut off the Japanese base at Rabaul from the rest of New Britain. Around 40 Australians had been killed and 130 wounded in the actions.

Periodic clashes continued. But Australian forces kept up the cordon until the Japanese formally surrendered the Rabaul garrison on 6 September 1945.

Australian forces liberated Rabaul, rescuing prisoners of war and civilian internees of many nationalities.