Backed by Japan, Zhang successfully influenced politics in the Republic of China during the early 1920s. In fall of 1924 during the Second Zhili–Fengtian War, he invaded and gained control of Peking, including the internationally recognized government, in April 1926. His appointment as grand marshal of the Republic of China in June 1927 represented the height of his success, but was quickly followed by defeat: the economy of Manchuria, the basis of his power, was overtaxed by his adventurism and collapsed in the winter of 1927; and he was defeated by the National Revolutionary Army of the Kuomintang under Generalissimo Chiang Kai-shek in May 1928. Leaving Beijing in early June to return to Manchuria, he was killed by a bomb planted by infuriated Kwantung officers on 4 June 1928; his brief reign presaged the end of Chinese warlordism by December.