The Chinese Communist Party took control of China by winning a long civil war. This war can be said to have started in 1927. It ended in 1949 when the communists, led by Mao Zedong, finally defeated the Kuomintang, who fled to Taiwan. There was a pause in the war during World War II. During that time, the communists and the nationalists both worked together (though with the Americans to oppose the Japanese who had invaded China in the late 1930s. However, once the Japanese were defeated, the Chinese factions took up fighting with one another again.