On 18 September 1931, Japan invaded Manchuria in China. The area was an industrialised region known for its rich mineral and coal reserves.
The initial invasion was the Mukden Incident, the first of many skirmishes between China and Japan.
One of the most horrific incidents in history was that of the Nanjing Massacre, also known as the Rape of Nanjing, which caused complete destruction of life and property at the hands of the Japanese.