Communists being arrested by the Guomindang

The 1927 Massacre of Shanghai, was a purging of communists ordered by Chinese general Chiang Kai-shek during the Northern Expedition. Prior to the expedition, the two factions, the Guomindang and the Communist Party of China, were allied under Sun Yat-sen. After Sun's death, the Communists became the political administrators, while Chiang became the Commander-in-Chief of the armed forces. Together they launched the Northern Expedition, in an attempt to remove China's Warlords. As the armies reconquered provinces, the communists began implementing peasant-oriented land reform, angering the right-wing members of the Guomindang. The communists further angered the conservatives when they moved the capital to Wuhan.

    At one point, the Communist party, along with the Guomindang, retook Shanghai from a Warlord. The communists took over the city, alarming the Guomindang with their influence and power. They organized protests and labor unions, and they attacked foreigners. Eventually, the Guomindang decided that things had gone far enough, and they decided that the Communist Party of China needed to be purged. They began having the army arrest any communists they could find, and to disarm their militias. Thousands were arrested, killed, or went missing. This event caused the Communist party to denounce any alliance with the Guomindang, and it sparked the Chinese Civil War.