Son of a prosperous peasant, Mao was born in Hunan province on December 26, 1893. Although he worked in the fields from an early age, Mao also received enough schooling to develop an interest in learning. This drew him back to school at age 16. Next, he worked at various teaching jobs and became active in radical student groups. In 1921 he was a founding member of the Chinese Communist Party. Soon afterward, he began to develop his theory of the revolutionary potential of the peasantry, which deviated from the traditional Marxist-Leninist emphasis on the industrial proletariat.

After the bloody communist fallout with Nationalist Chiang Kai-shek in 1927, Mao established a base in the southern Kiangsi province. He began to put into practice his ideas about a revolutionary peasantry by way of a guerrilla war against the government. In 1934, Chiang's armies closed in, but the communist forces escaped for their "Long March" to the northwestern Shenshi province. When the Chinese civil war resumed after 1945, Mao and his movement were able to use their rural foundation to outmaneuver and eventually overwhelm the Nationalists. Mao proclaimed the People's Republic of China on October 1, 1949.

In 1950, China concluded a mutual defense pact with Stalin's Soviet Union, and together Moscow and Beijing supported North Korea in its attack on South Korea. Soviet-Chinese relations deteriorated during the 1950s, when both sides competed for pre-eminence in the world communist movement, particularly in the Third World. Relations during the 1960s were outright tense, and in 1969 the sides even fought a brief border war. The Sino-Soviet split helped Mao's regime accept a normalization of relations with the United States. Although Beijing continued to resent Washington's support for Taiwan, in 1972 Mao welcomed U.S. President Richard Nixon in Beijing.

Domestically, Mao's record is dominated by two disastrous initiatives: the "Great Leap Forward," a broad campaign to organize peasants into communes during the late 1950s that resulted in mass starvation and repression; and the "Cultural Revolution," a youth- and army-driven nationwide campaign for ideological purity, again resulting in widespread repression and death. The Cultural Revolution was still sputtering under the leadership of Mao's wife, Chiang Ch'ing, when Mao died on September 9, 1976, at age 82.