The Shanghai Massacre of 1927, also known as the April 12 Incident, sparked the Chinese Civil War between the Nationalists and the Communists. In early 1927, the KMT and CPC formed the First United Front to battle Northern China’s warlords.
However, tensions grew between the two camps due to their widely divergent philosophies. The KMT, led by Chiang Kai-shek, embraced nationalist and capitalist ideas, whilst the Communists, led by Mao Zedong and others, advocated for Marxist-Leninist principles.
On April 12, 1927, Chiang Kai-shek directed a harsh purge of Communists and their supporters in Shanghai. Thousands of communists, trade unionists, and left-wing activists were jailed, and many were killed or disappeared. The Shanghai Massacre was a turning point in Chinese history, as it formally initiated the long and bloody conflict between the Nationalists and Communists.