What began as a local military incident near the Marco Polo Bridge on the outskirts of Beijing developed into the Second Sino-Japanese War, which later became part of the wider Second World War in Asia.

Approximately 300 B-52 bombers dropped thousands of tons of incendiaries over the eastern districts of Tokyo, causing firestorms that overwhelmed firefighting efforts and killed around 100,000 people, with many more injured.

The group, which included six foreign Franciscan friars, three Japanese Jesuits, and seventeen Japanese lay Christians, was sentenced to death by Toyotomi Hideyoshi after statements from a shipwrecked crew suggested that missionaries prepared the way for military conquest.

The Japanese used approximately 60,000 POWs, mainly British, Dutch, Australian, and American, to construct the railway alongside an estimated 180,000 to 250,000 Asian civilians. It is estimated that around 12,000 Allied prisoners and up to 90,000 civilians died during construction.