World War II: Japanese forces invade the island of Ambon in the Dutch East Indies. Some 300 captured Allied troops are killed after the surrender. One-quarter of the remaining POWs remain alive at the end of the war.

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 Ambon occurred on Ambon Island in the Dutch East Indies, as part of the Japanese offensive on the Dutch colony during World War II. In the face of a combined defense by Dutch and Australian troops, Japanese forces conquered the island and its strategic airfield in several days. In the aftermath of the fighting, a major massacre of many Dutch and Australian prisoners of war by the Imperial Japanese Army (IJA) followed. Following the war, many of the IJA personnel were tried for war crimes.

The Dutch East Indies, also known as the Netherlands East Indies, was a Dutch colony with territory mostly comprising the modern state of Indonesia, which declared independence on 17 August 1945. Following the Indonesian War of Independence, Indonesia and the Netherlands made peace in 1949. In the Anglo-Dutch Treaty of 1824, the Dutch ceded the governorate of Dutch Malacca to Britain, leading to its eventual incorporation into Malacca (state) of modern Malaysia.