Mao launched a movement called the Cultural Revolution, which aimed to remove opposition to the Communist Party. Mao's new supporters were called the Red Guards. They sought out and punished people who spoke against Mao's principals or who had contact with Western people or ideas.
Mao promotes a "Great Leap Forward" in economic development, relying on mass mobilization, the commune system, and indigenous methods. The effort fails for the most part because of administrative weakness aggravated by bad weather.
In 1949, the Communists defeated the Nationalists, forcing Chiang Kai-shek to flee to Taiwan. On October 1, Mao declared China a Communist state called the People's Republic of China.