In May 1929, upset over what he perceived as Jiang's concentration of power in his own hands, Feng declared his independence of the Nationalist government. In February 1930, Feng and another warlord, Yan Xishan (Yen Hsi-shan), known as the northern coalition, rebelled against Jiang. They received support from the so-called Guangxi (Kwangsi) clique of Bai Chongxi (Pai Ch'ung-hsi), Li Zongren (Li Tsung-jen), Wang Jingwei (Wang Ching-wei), and Zhang Fakui (Chang Fa-k'uei) from Guangdong (Kwangtung). Defeated in October, Feng was forced to relinquish control of his forces, which came under the Nationalist government, and he went into seclusion.
After the September 1931 Mukden (Shenyang) Incident in Liaoning, Feng returned to public life, denouncing Jiang's failure to resist the Japanese advance in northern China. In 1933, Feng commanded a voluntary army to fight the Japanese, but it was quickly disbanded because of Jiang's opposition and increased Japanese military pressure. Feng retired to Shandong until 1936, when he was appointed vice chairman of the GMD's Military Affairs Commission, serving in Nanjing (Nanking), Jiangsu (Kiangsu).
With the beginning of the Sino-Japanese War in 1937, Feng became commander in chief of the Third War Zone (southern Jiangsu and Zhejiang [Chekiang]), defending Shanghai, which fell at the year's end. In February 1938, Feng became commander in chief of the Sixth War Zone to defend the communication route between Nanjing and Hebei's Tianjin (Tientsin), which the Japanese took that autumn. In October, Feng followed the Nationalist government to Chongqing (Chungking), Sichuan (Szechwan), where he remained militarily inactive until the war's end.
In September 1946, Feng was sent to the United States to study irrigation and conservation facilities. He never returned but took up residence in Berkeley, California, giving public lectures in which he held Jiang responsible for the Chinese Civil War. On 1 September 1948, Feng died in a fire aboard a ship in the Black Sea while returning to China to serve the new Communist government. On 15 October 1954, to honor his patriotism, leaders of the People's Republic of China caused Feng's ashes to be buried at Taishan (T'ai-shan) in Shandong Province.
Bonavia, David. China's Warlords. Hong Kong: Oxford University Press, 1995.; Sheridan, James E. Chinese Warlord: The Career of Feng Yu-hsiang. Stanford, CA: Stanford University Press, 1966.