Beiyang Army in the context of "National Protection War"

The Republic of China (ROC) was established 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 the seat of China from the ROC 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 km (4.4 million sq mi) of territory, and its population of 541 million in 1949 made it the most populous country in the world.

The Republic of China was officially proclaimed on 1 January 1912 by revolutionaries under Sun Yat-sen, the ROC's founder and provisional president of the new republic, following the success of the 1911 Revolution. Puyi, the final Qing emperor, abdicated on 12 February 1912. Sun served briefly before handing the presidency to Yuan Shikai, the leader of the Beiyang Army. Yuan's Beiyang government quickly became authoritarian and exerted military power over the administration; in 1915, Yuan attempted to replace the Republic with his own imperial dynasty until popular unrest forced him to back down. When Yuan died in 1916, the country fragmented between local commanders of the Beiyang Army, beginning the Warlord Era defined by decentralized conflicts between rival cliques. At times, the most powerful of these cliques used their control of Beijing to assert claims to govern the entire Republic.

The 1911 Revolution, also known as the Xinhai Revolution or Hsinhai Revolution, ended China's last imperial dynasty, the Qing dynasty, and led to the establishment of the Republic of China (ROC). The revolution was the culmination of a decade of agitation, revolts, and uprisings. Its success marked the collapse of the Chinese monarchy, the end of over two millennia of imperial rule in China and the 267-year reign of the Qing, and the beginning of China's early republican era.

The Qing had long struggled to reform the government and resist foreign aggression, but conservatives in the Qing court opposed the program of reforms after 1900 as too radical and reformers considered it too slow. Several factions, including underground anti-Qing groups, revolutionaries in exile, reformers who wanted to save the monarchy by modernizing it, and activists across the country debated how or whether to overthrow the Qing dynasty. The flashpoint came on 10 October 1911 with the Wuchang Uprising, an armed rebellion by members of the New Army. Similar revolts then broke out spontaneously around the country, and revolutionaries in every province renounced the Qing dynasty. On 1 November 1911, the Qing court appointed Yuan Shikai (leader of the Beiyang Army) as prime minister, and he began negotiations with the revolutionaries.

The Warlord Era was the period in the history of the Republic of China between 1916 and 1928, when control of the country was divided between rival military cliques of the Beiyang Army and other regional factions. It began after the death of Yuan Shikai, the President of China after the Xinhai Revolution had overthrown the Qing dynasty and established the Republic of China in 1912. Yuan's death on 6 June 1916 created a power vacuum which was filled by military strongmen and widespread violence, chaos, and oppression. The Nationalist Kuomintang (KMT) government of Sun Yat-sen, based in Guangzhou, began to contest Yuan's Beiyang government based in Beijing for recognition as the legitimate government of China.

The most powerful cliques were the Zhili clique led by Feng Guozhang, who controlled several northern provinces; the Anhui clique led by Duan Qirui, based in several southeastern provinces; and the Fengtian clique led by Zhang Zuolin, based in Manchuria. The three cliques often engaged in conflict for territory and hegemony. In mid-1917, after Yuan's successor Li Yuanhong attempted to remove Duan as premier, the general Zhang Xun forced Li to resign and made a brief attempt to restore the Qing dynasty, which was quashed by Duan's troops. Feng became the acting president, but was forced to step down by Duan in late 1918 and was replaced by Xu Shichang. In mid-1920, the new Zhili clique leaders, Cao Kun and Wu Peifu, defeated Duan in the Zhili–Anhui War in an alliance with Zhang Zuolin. A power struggle broke out between Cao and Zhang which ended with Cao's victory in the First Zhili–Fengtian War in 1922. Cao was president until 1924, when during the Second Zhili–Fengtian War he was betrayed by his subordinate Feng Yuxiang, who joined with Zhang to stage a coup against Cao. Feng and Zhang shared power and recalled Duan to serve as president before Zhang removed them both in 1926; in 1927, he declared himself Generalissimo.

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 second phase of the Expedition began in January 1928, when Chiang resumed command. By April 1928, the nationalist forces had advanced to the Yellow River. With the assistance of allied warlords, including Yan Xishan and Feng Yuxiang, the nationalist forces secured a series of decisive victories against the Beiyang Army. As they approached Beijing, Zhang Zuolin, leader of the Manchuria-based Fengtian clique, was forced to flee and was later assassinated shortly thereafter by the Japanese. His son, Zhang Xueliang, took over as the leader of the Fengtian clique, and in December 1928, announced that Manchuria would accept the authority of the nationalist government in Nanjing. With the final piece of China under KMT control, the Northern Expedition concluded successfully and China was reunified, heralding the start of the Nanjing decade.

Yuan Shikai (traditional Chinese: 袁世凱; simplified Chinese: 袁世凯; pinyin: Yuán Shìkǎi; Wade–Giles: Yüan Shih-k'ai; 16 September 1859 – 6 June 1916) was a Chinese general and statesman who served as the second provisional president and the first official president of the Republic of China, head of the Beiyang government from 1912 to 1916 and Emperor of the Chinese Empire from 1915 to 1916. A major political figure during the late Qing regime, he spearheaded a number of major modernisation programs and reforms and played a decisive role in securing the abdication of Puyi in 1912, which marked the collapse of the Qing regime and the end of imperial rule in China.

Born to an affluent Han family in Xiangcheng county, Yuan began his career in the Huai Army. He was sent to Joseon to head a Qing garrison in Seoul and was appointed imperial resident and supreme adviser to the Korean government after thwarting the Gapsin Coup in 1885. He was recalled to China shortly before the outbreak of the First Sino-Japanese War, and received command of the first New Army, which paved the way for his rise to power. In 1898, Yuan formed an alliance with Empress Dowager Cixi and helped bring an end to the Guangxu Emperor's Hundred Days' Reform. Promoted to Viceroy of Zhili in 1902, Yuan quickly expanded the Beiyang Army into the best trained and most effective military force in China. He played an active role in the Late Qing reforms, which included the abolition of the imperial examination. Upon the death of Cixi in 1908 he fell from power and was forced into exile, but retained the loyalty of the Beiyang Army and as such remained an influential figure.

The Beiyang government was the internationally recognized government of the Republic of China between 1912 and 1928, based in Beijing. It was dominated by the generals of the Beiyang Army, giving it its name.

Beiyang general Yuan Shikai gave Sun Yat-sen the military support he needed to establish the Republic of China in 1912. Through his control of the army, Yuan was quickly able to dominate the new Republic as its president. Although the government and the state were nominally under civilian control through the Republic's constitution, Yuan and his generals were effectively in charge of it. After Yuan's death in 1916, the army split into various warlord factions competing for power, leading to a period of civil war called the Warlord Era. Nevertheless, the government maintained its legitimacy among the great powers, receiving diplomatic recognition, foreign loans, and access to tax and customs revenue.