護法運動
In the 1920s, the Beiyang government based in Beijing was internationally recognised as the legitimate Chinese government. Much of the country, however, was not under its control, being ruled by a patchwork of warlords. The Kuomintang (KMT), based in Guangzhou (Canton), aspired to be the party of national liberation. Since the conclusion of the Constitutional Protection Movement in 1922, the KMT had been bolstering its ranks to prepare for an expedition against the northern warlords in Beijing, with the goal of reunifying China. This preparation involved improving both the political and military strength of the KMT. Before his death in March 1925, Sun Yat-sen, the founder of the Republic of China and co-founder of the KMT, was supportive of Sino-Soviet co-operation, which had involved forming the First United Front with the Chinese Communist Party (CCP). The military arm of the KMT was the National Revolutionary Army (NRA). Chiang Kai-shek, who had emerged as Sun's protégé as early as 1922, was appointed commandant of the Whampoa Military Academy in 1924, and quickly emerged as a contender for the position of Sun's successor in the aftermath of his death.