Chiang Kai-shek accepts the post of commander-in-chief of the National Revolutionary Army, marking the beginning of the Northern Expedition to unite China under the rule of the Nationalist government.

Chiang Kai-shek was a Chinese politician, revolutionary, and general who led the Republic of China (ROC) from 1928 until his death in 1975. His government was based in mainland China until it was defeated in the Chinese Civil War by the Chinese Communist Party (CCP) in 1949, after which he continued to lead the Republic of China on the island of Taiwan. Chiang served as leader of the Nationalist Kuomintang (KMT) party and the commander-in-chief of the National Revolutionary Army (NRA) from 1926 until his death.

The National Revolutionary Army served as the military arm of the Chinese Nationalist Party from 1924 until 1947.

The Northern Expedition was a military campaign launched by the National Revolutionary Army (NRA) of the Kuomintang (KMT) against the Beiyang government and other regional warlords in 1926. The purpose of the campaign was to reunify China, which had become fragmented in the aftermath of the 1911 Revolution. The expedition was led by Generalissimo Chiang Kai-shek, and was divided into two phases. The first phase ended in a 1927 political split between two factions of the KMT: the right-leaning Nanjing faction, led by Chiang, and the left-leaning faction in Wuhan, led by Wang Jingwei. The split was partially motivated by Chiang's Shanghai Massacre of Communists within the KMT, which marked the end of the First United Front. In an effort to mend this schism, Chiang Kai-shek stepped down as the commander of the NRA in August 1927, and went into exile in Japan.

The Republic of China (ROC) began on 1 January 1912 as a sovereign state in mainland China following the 1911 Revolution, which overthrew the Manchu-led Qing dynasty and ended China's imperial history. From 1927, the Kuomintang (KMT) reunified the country and initially ruled it as a one-party state with Nanjing as the national capital. In 1949, the KMT-led government was defeated in the Chinese Civil War and lost control of the mainland to the Chinese Communist Party (CCP). The CCP established the People's Republic of China (PRC) while the ROC was forced to retreat to Taiwan; the ROC retains control over the Taiwan Area, and its political status remains disputed. The ROC is recorded as a founding member of both the League of Nations and the United Nations, and previously held a permanent seat on the United Nations Security Council until 1971, when the PRC took China's seat in the United Nations General Assembly Resolution 2758. It was also a member of the Universal Postal Union and the International Olympic Committee. The ROC claimed 11.4 million km² (4.4 million sq mi) of territory, and its population of 541 million in 1949 made it the most populous country in the world.