Long March (1934-35), the 6,000-mile (10,000-kilometre) historic trek of the Chinese Communists, which resulted in the relocation of the Communist revolutionary base from Southeast China to Northwest China and in the emergence of Mao Zedong as the undisputed party leader. Fighting Nationalist under Chiang Kai-shek throughout their journey, the Communist troops crossed 18 mountain ranges and 24 rivers to reach the northwestern province of Shensi. The heroism attributed to the Long March inspired many young Chinese to join the Chinese Communist Party during the late 1930s and early 1940s. Between 1930 and 1934 Chiang Kai-shek launched a series of five military encirclement campaigns against the Chinese Communists in an attempt to annihilate their base area (the Kiangsi Soviet) on the Kiangsi-Fukien border in southeastern China. The Communists successfully fought off the first four campaigns using tactics of mobile infiltration and guerrilla warfare developed by Mao. In the fifth campaign Chiang mustered about 700,000 troops and established a series of cement blockhouses around the Communist positions. The Chinese Communist Central Committee, which had removed Mao from the leadership early in 1934, abandoned his guerrilla warfare strategy and used regular positional warfare tactics against the better-armed and more numerous Nationalist forces. As a result the Communist forces suffered heavy losses and were nearly crushed. On Oct. 15, 1934, the remaining 85,000 troops, 15,000 administrative personnel, and 35 women broke through the Nationalist lines at their weakest points and fled westward. Mao, at the time of the Communists' departure, was not in control of events; Zhu De was the commander of the army, and Zhou Enlai was the political commissar of the party. The first three months of the march were disastrous for the Communists: subjected to constant bombardment from Chiang's air force and repeated attacks from his ground troops, they lost more than half of their army. Morale was low when they arrived in Tsun-i, in the southwestern province of Kweichow, but at a conference in Tsun-i in January 1935 Mao was able to gather enough support to establish his dominance of the party. The march then headed toward Northwest China, near the safety of the Soviet border and close to the territory occupied by the Japanese in northeastern China. In June 1935 a force under Chang Kuo-t'ao, a longtime Communist leader, joined the main army, and at Mao-erh-kai in western Szechwan a power struggle ensued between Mao and Chang. Chang's group, accompanied by Zhu De, headed toward the extreme southwestern part of China. The main body under Mao proceeded toward northern Shensi, where the Communist leaders Gao Gang and Liu Zhidan had built up another Soviet area. Mao arrived at this destination in October 1935 along with only about 8,000 survivors. Along the route some Communists had left the march to mobilize the peasantry; but most of the missing had been eliminated by fighting, disease, and starvation. Among the missing were Mao's two small children and his younger brother, Mao Zetan. Mao's troops joined the local Red Army contingent of 7,000 men, and other units (including that of Zhu De) swelled their total strength by late 1936 to about 30,000 troops. In December 1936 the Communists moved to the nearby district of Yen-an in Shensi, where they remained throughout the war with the Japanese. The Long March decisively established Mao's leadership of the Chinese Communist Party, and it enabled the embattled Communists to reach a base area beyond the direct control of the Nationalists. From their base at Yen-an the Communists grew in strength and eventually defeated the Nationalists in the struggle to control mainland China.