The Japan-China War started in July 1937 when the Japanese claimed that they were fired on by Chinese troops at the Marco Polo Bridge near Beijing. Using this as an excuse, the Japanese launched a full-scale invasion of China using the conquered Manchuria as a launching base for their troops.
The Japanese came up against little organized resistance. The Guomintang put up little resistance though they were up against a formidable enemy. In November 1937, China’s most important port, Shanghai, fell and Nanjing (Nanking), Chiang Kai-shek’s capital, fell in December 1937.