Chinese military and political leader Chiang Kai-shek joined the Chinese Nationalist Party (known as the Kuomintang, or KMT) in 1918. Succeeding party founder Sun Yat-sen as KMT leader in 1925, he expelled Chinese communists from the party and led a successful unification of China. Despite a professed focus on reform, Chiang’s government concentrated on battling Communism within China as well as confronting Japanese aggression. When the Allies declared war on Japan in 1941, China took its place among the Big Four. Civil war broke out in 1946, ending in a victory by Mao Zedong’s Communist forces and the creation of the People’s Republic of China. From 1949 until his death, Chiang led the KMT government in exile in Taiwan, which many countries continued to recognize as China’s legitimate government.