Chiang Kai-shek (October 31, 1887  April 5, 1975) was a political and military leader of 20th century China. He is known as Ji?ng Ji?sh? or Ji?ng Zh?ngzh?ng in Mandarin. Chiang was an influential member of the Nationalist Party, the Kuomintang (KMT), and was a close ally of Sun Yat-sen. He became the Commandant of the Kuomintang's Whampoa Military Academy, and took Sun's place as leader of the KMT when Sun died in 1925. In 1926, Chiang led the Northern Expedition to unify the country, becoming China's nominal leader. He served as Chairman of the National Military Council of the Nationalist government of the Republic of China (ROC) from 1928 to 1948. Chiang led China in the Second Sino-Japanese War, during which the Nationalist government's power severely weakened, but his prominence grew. Chiang's Nationalists engaged in a long standing civil war with the Chinese Communist Party (CCP). After the Japanese surrender in 1945, Chiang once again became embroiled in a bloody civil war with the Communist Party of China. In 1949 the CCP defeated the Nationalists, forcing the Nationalist government to retreat to Taiwan, where martial law was imposed, and from where the government continued to declare its intention to take back mainland China. Chiang ruled the island securely as the President of the Republic of China and Director-General of the Kuomintang until his death in 1975.