The Chinese Civil War, spanning from 1927 to 1949, was a conflict between the Republic of China led by the Kuomintang and the Chinese Communist Party. It witnessed two main phases: from 1927 to 1937, where the Nationalists mostly controlled China, and from 1937 to 1945, during which the war was briefly suspended due to the Japanese invasion and the Second United Front. However, conflicts between the Nationalists and Communists persisted. After World War II, as Japan's defeat neared, the civil war reignited, culminating in Communist control of mainland China by 1949. Following this, the Communists established the People's Republic of China, compelling the Republic of China's leadership to retreat to Taiwan. Since the 1950s, a prolonged political and military standoff between the two sides of the Taiwan Strait has persisted, each claiming to be the legitimate government of all China. Despite a cessation of fire after the Second Taiwan Strait Crisis in 1979, no official armistice or peace treaty has been agreed upon.

Chinese Civil War - Wikipedia