Historians call the Kuomintang and Communist Party twins of the same mother - the Soviet Communist Party.
The KMT was founded in August 1912 and the Communist Party in July 1921. Both were revolutionary parties that aimed to modernise and reform China after centuries of feudal and imperial rule.
In the 1920s, the KMT received aid from the Soviet Union; its advisers reorganised the party on the lines of the Soviet party, a Leninist structure that lasted until the 1990s. The Soviet advisers told members of the Communist Party to co-operate with it and encouraged them to join, while maintaining their separate party identity. In 1923, Chiang Kai-shek was sent to Moscow for several months of political and military study, especially in propaganda and mass mobilisations.
The Whampoa Military Academy in Guangzhou trained members of both the KMT and the Communist Party, including Lin Biao, who went on to play major roles in the war against Japan and the civil war. Among the main lecturers were Soviet officers who taught military subjects, history and political agitation. Zhou Enlai was director of the academy's political department.
The two parties worked together until Chiang organised a large-scale purge of the Communists in April 1927, known as the 'Shanghai Massacre'. He believed he was strong enough to rule China without them. The two parties went to war against each other until December 1936, when Chiang was kidnapped in Xian and forced to join forces with the Communists to fight Japan. This alliance lasted until Japan's surrender, when the civil war resumed.
Six decades later, the KMT remains the second-largest and best-organised party in Greater China. Although it has sold many of its assets, as a result of public pressure, it remains wealthy.