Sun Yat-sen died of cancer in Beijing in March 1925, but the Nationalist movement he had helped to initiate was gaining momentum. During the summer of 1925, Chiang, as commander-in-chief of the National Revolutionary Army, set out on the long-delayed Northern Expedition against the northern warlords. Within nine months, half of China had been conquered. By 1926, however, the Kuomintang had divided into left- and right-wing factions, and the Communist bloc within it was also growing. In March 1926, after thwarting a kidnapping attempt against him, Chiang abruptly dismissed his Soviet advisers, imposed restrictions on CCP members' participation in the top leadership, and emerged as the preeminent Kuomintang leader. The Soviet Union, still hoping to prevent a split between Chiang and the CCP, ordered Communist underground activities to facilitate the Northern Expedition, which was finally launched by Chiang from Guangzhou in July 1926.

In early 1927 the Kuomintang- CCP rivalry led to a split in the revolutionary ranks. The CCP and the left wing of the Kuomintang had decided to move the seat of the Nationalist government from Guangzhou to Wuhan. But Chiang, whose Northern Expedition was proving successful, set his forces to destroying the Shanghai CCP apparatus and established an anti-Communist government at Nanjing in April 1927. There now were three capitals in China: the internationally recognized warlord regime in Beijing; the Communist and left-wing Kuomintang regime at Wuhan; and the right-wing civilian-military regime at Nanjing, which would remain the Nationalist capital for the next decade.

But in mid-1927 the CCP was at a low ebb. The Communists had been expelled from Wuhan by their left-wing Kuomintang allies, who in turn were toppled by a military regime. By 1928 all of China was at least nominally under Chiang's control, and the Nanjing government received prompt international recognition as the sole legitimate government of China. The Nationalist government announced that in conformity with Sun Yat-sen's formula for the three stages of revolution--military unification, political tutelage, and constitutional democracy--China had reached the end of the first phase and would embark on the second, which would be under Kuomintang direction.

Chinese civil war began with the Shanghai Massacre (April 12). Kuomintang army forces led by Chiang Kai-shek attacked their Communist allies in Shanghai and several other cities, executing 5,000 to 6,000 of those captured.

In the Nanchang Uprising (August), the first major Kuomintang-Communist engagement of the war, Communist forces under Zhu De (Chu Teh) were defeated, withdrawing to the Ching-kang Mountains of western Kiangsi.

The comintern cause appeared bankrupt. A new policy was instituted calling on the CCP to foment armed insurrections in both urban and rural areas in preparation for an expected rising tide of revolution. Unsuccessful attempts were made by Communists to take cities such as Nanchang, Changsha, Shantou, and Guangzhou, and an armed rural insurrection, known as the Autumn Harvest Uprising, was staged by peasants in Hunan Province. The insurrection was led by Mao Zedong (1893-1976), who would later become chairman of the CCP and head of state of the People's Republic of China. Mao was of peasant origins and was one of the founders of the CCP.

Mao Zedong, who had become a Marxist at the time of the emergence of the May Fourth Movement (he was working as a librarian at Beijing University), had boundless faith in the revolutionary potential of the peasantry. He advocated that revolution in China focus on them rather than on the urban proletariat, as prescribed by orthodox Marxist-Leninist theoreticians. Despite the failure of the Autumn Harvest Uprising of 1927, Mao continued to work among the peasants of Hunan Province. Without waiting for the sanction of the CCP center, then in Shanghai, he began establishing peasant based soviets (Communist-run local governments) along the border between Hunan and Jiangxi provinces. In collaboration with military commander Zhu De (1886-1976), Mao turned the local peasants into a politicized guerrilla force. By the winter of 1927-28, the combined "peasants' and workers'" army had some 10,000 troops.

In the Battle of Ch'angsha (July), Kuomintang forces decisively defeated Communist attempts to take Ch'angsha and several other central Chinese cities, forcing the Communist forces to flee into the mountains of western Kiangsi, there developing the Kiangsi Soviet.

Mao's prestige rose steadily after the failure of the Comintern-directed urban insurrections.

Through the mediatory influence of the United States a military truce was arranged in January 1946, but battles between Nationalists and Communists soon resumed. Realizing that American efforts short of large-scale armed intervention could not stop the war, the United States withdrew the American mission, headed by General George C. Marshall, in early 1947. The civil war, in which the United States aided the Nationalists with massive economic loans but no military support, became more widespread. Battles raged not only for territories but also for the allegiance of cross sections of the population.