Nanjing (then spelled "Nanking" in English) was China's capital city during the 1920s and 1930s. At that time, Japan was an empire that included Korea and Taiwan. During the 1930s, Japan started the Second Sino-Japanese War and tried to take over all of China. This became part of World War II, as Japan's friend Germany took over Poland and Italy joined their wars and started some of its own. When the Japanese army got to Nanjing in December 1937 and January 1938, it did not only fight the Chinese army; it also killed many other people who were not fighting at all. It also committed many, many war crimes against the people in the city. It is even hard to count how many people were killed or hurt in all, because the Japanese treated the bodies and the people so badly. The Chinese government says 300,000 people were killed and more were hurt.