The uprising that led to the establishment of the People's Republic of China in 1949 was the Chinese Civil War, which primarily pitted the Communist Party of China (CPC) against the Nationalist Party (Kuomintang). The war resumed after World War II and culminated in a decisive victory for the communists. Led by Mao Zedong, the CPC's success was fueled by popular support and effective guerrilla warfare tactics. On October 1, 1949, Mao proclaimed the founding of the People's Republic of China, marking a significant shift in Chinese politics, society, and governance following decades of turmoil and conflict.