Battle of Port Moresby

Strategic situation

The US officially entered the Second World War after Japan bombed Pearl Harbor on 7 December 1941. Japan sought to expand its territory across South-East Asia and the Pacific.

On 23 January 1942, Japanese forces invaded Rabaul, on the island of New Britain in northern New Guinea. Several thousand soldiers and civilians, including nearly 1,200 Australians, would die as a result of the Japanese occupation of New Britain.

Rabaul became a major Japanese base. But it was too far north to be used as a base for operations Japan wished to make south of New Britain. The Japanese decided to take Port Moresby, the capital of the Australian Territory of Papua.

Port Moresby had many strategic advantages. These included a sheltered, deep-water harbour, docks, airfields, storage sheds and hospitals. It also had clean water and other infrastructure needed to support air, land and other operations.

Japan wanted to capture territory across the Pacific to stop Australia providing strategic support to the United States military.

The bombing of Port Moresby

Japan began bombing the Australian garrison at Port Moresby on 3 February 1942. This was to prepare for a seaborne invasion.

On 15 February, the Australian civilian administration in Papua and New Guinea was replaced with military rule. Major General Basil Morris commanded the new Australian New Guinea Administrative Unit.

At first, Australia had no aircraft in Port Moresby. The defence of Port Moresby relied on First World War field guns and howitzers, the 23rd Heavy Anti-Aircraft Battery, engineers, and some members of the 17th Anti-tank Battery.

The Royal Australian Air Force (RAAF) sent elements of No. 75 Squadron Kittyhawks based in Townsville to Port Moresby in March 1942.

By the time the Kittyhawks arrived, the Australian troops were desperate. They had nicknamed the aeroplanes 'Tomorrowhawks' and 'Neverhawks' because they were so late arriving. When they eventually arrived, the troops were so surprised that the anti-aircraft gunners fired at them. They thought they were Japanese Zero fighters.

Within two hours of arriving, a Kittyhawk had shot down a Japanese aircraft. But over the next nine days, the Australians lost 11 aircraft.

Squadron Leader John Francis Jackson DFC was the commanding officer of No. 75 Squadron. Despite its losses, he led many successful sorties against Japanese forces. He was shot down near Lae but survived and made his way back to Port Moresby. On 28 April 1942, he was killed when he led the RAAF's five remaining Kittyhawks to intercept attacking Japanese bombers and their escort. Present day PNG’s main international airport in Port Moresby, Jacksons International, is named after him.

On 31 March, the United States Army Air Force (USAAF) joined the RAAF in fighting the Japanese. The 8th Bombardment Squadron with A-24 bombers arrived first. Six P-39 Airacobra fighter aircraft of the 36th Pursuit Squadron joined them for two weeks in May. Later, the full 36th Pursuit Squadron and the 35th Pursuit Squadron arrived to relieve No. 75 Squadron RAAF.

The Battle of the Coral Sea, and the US capture of Guadalcanal, diverted Japanese forces. This removed the immediate threat to Port Moresby. But the threat from Japanese forces in the north of New Guinea remained.