World War II: Japanese forces attacked the Australian base at Milne Bay on the eastern tip of New Guinea.

World War II or the Second World War was a global conflict between two coalitions: the Allies and the Axis powers. Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks and aircraft played major roles, enabling the strategic bombing of cities and delivery of the first and only nuclear weapons ever used in war. World War II is the deadliest conflict in history, causing the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Germany, Austria, Japan, and Korea were occupied, and German and Japanese leaders were tried for war crimes.

The Battle of Milne Bay, also known as Operation RE or the Battle of Rabi (ラビの戦い) by the Japanese, was a battle of the Pacific campaign of World War II. Japanese naval infantry, known as Kaigun Tokubetsu Rikusentai, with two small tanks attacked the Allied airfields at Milne Bay that had been established on the eastern tip of New Guinea. Due to poor intelligence work, the Japanese miscalculated the size of the predominantly Australian garrison and, believing that the airfields were defended by only two or three companies, initially landed a force roughly equivalent in size to one battalion on 25 August 1942. The Allies, forewarned by intelligence from Ultra, had heavily reinforced the garrison.

Milne Bay is a large bay in Milne Bay Province, south-eastern Papua New Guinea. More than 35 kilometres long and over 15 kilometres wide, Milne Bay is a sheltered deep-water harbor accessible via Ward Hunt Strait. It is surrounded by the heavily wooded Stirling Range to the north and south, and on the northern shore, a narrow coastal strip, soggy with sago and mangrove swamps. The bay is named after Sir Alexander Milne.