The Republic of China established its governance over Mainland China on 1 January 1912 following the Xinhai Revolution, which overthrew the Manchu-led Qing dynasty and ended China's imperial history. The Beiyang government in Beijing was the internationally recognized government of the ROC from 1912 to 1928, with regional warlords occupying parts of the country after the death of Beiyang leader Yuan Shikai in 1916. In 1926, the Kuomintang (KMT) launched the Northern Expedition, which eventually reunified the country in 1928. The KMT established the Nationalist government and governed the ROC as a one-party state with Nanjing as the capital. In 1949, the KMT was defeated in the Chinese Civil War by the Chinese Communist Party (CCP) and the ROC government retreated to Taiwan, where it remains to this date. The ROC is recorded as a founding member of both the League of Nations and the United Nations. It 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.
The Republic of China was officially proclaimed on 1 January 1912 by revolutionaries under Sun Yat-sen, who became provisional president of the new republic. 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. The 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. After he died in 1916, the country fragmented between local commanders of the Beiyang Army, commencing the Warlord Era defined by decentralized conflicts between rival cliques.
Meanwhile, the KMT under Sun attempted multiple times to establish a rival government in Guangzhou, eventually taking the city with help from the Soviet Union under the condition that the KMT form the First United Front with the CCP in order to go about reunifying China. Sun's death in 1925 precipitated a power struggle that eventually resulted in the rise of General Chiang Kai-shek to KMT chairmanship. By 1927, Chiang felt secure enough to end the alliance with the Soviets and purged the Communists before completing the Northern Expedition to achieve Sun's goal in 1928. Chiang subsequently ruled the country as a one-party state under the Dang Guo system, receiving international recognition as the representative of China.
While there was relative prosperity during the Nanjing decade (1927–1937), the ROC faced internal and external threats. The severely weakened CCP gradually rebuilt its strength by organizing peasants in the countryside. Surviving warlords who resented Chiang's consolidation of power led several uprisings, most significantly the Central Plains War. In 1931, Japan invaded Manchuria, followed by a full-scale invasion of China in 1937. World War II devastated the ROC, leading to enormous loss of life and material destruction. Japan surrendered in September 1945 and Taiwan was placed under Chinese administration. Civil war resumed, and the CCP's People's Liberation Army began to gain the upper hand in 1948. The People's Republic of China was proclaimed in October 1949 amid the ROC's exodus to Taiwan.
The Republic of China's first provisional president, Sun Yat-sen, chose Zhōnghuá Mínguó (中華民國; 'Chinese People's State') as the country's official Chinese name. The name was derived from the language of the Tongmenghui's 1905 party manifesto, which proclaimed that the four goals of the Chinese revolution were "to expel the Manchu rulers, revive China (Zhōnghuá), establish a people's state (mínguó), and distribute land equally among the people." On 15 July 1916, in his welcoming speech to the Cantonese delegates in Shanghai, Sun explained why the term mínguó (民國; 'people's country') was chosen over the gònghéguó (共和國). He associated the label gònghé (共和) with the limiting and authoritarianism-prone Euro-American models of representative republicanism. What he strived for was a more grass-roots model, which he termed zhíjiē mínquán (直接民權; 'direct people's rights'), and which he thought would allow more checks and balances by the people. Later on 20 October 1923, at a national conference for youths in Guangzhou, to explain the core idea behind mínguó (民國; 'people's country'), he pithily compared the phrase "Empire of China" (中華帝國; Zhōnghuá Dìguó; 'Chinese Emperor's Country') to "Republic of China" (中華民國; Zhōnghuá Mínguó; 'Chinese People's Country') in the form of a parallelism: an emperor's country is ruled by only one emperor (帝國是以皇帝一人為主), a people's country is ruled by all four hundred million people (民國是以四萬萬人為主). Both the "Beiyang Government" (from 1912 to 1928), and the "Nationalist Government" (from 1928 to 1949) used the name "Republic of China" as their official name. In Chinese, the official name was often shortened to Zhōngguó (中國; 'Middle Country'), Mínguó (民國; 'People's Country'), or Zhōnghuá (中華; 'Middle Huaxia').
The choice of the term mínguó (民國; 'people's country'; "republic") in 1912, as well as its similar semantic formation to dìguó (帝國; 'emperor's country'; "empire"), may have influenced the choice of the Korean term minguk (민국/民國) by the Provisional Government of the Republic of Korea (founded in 1919 within the Republic of China), which replaced Daehan Jeguk (대한제국/大韓帝國) with Daehan Minguk (대한민국/大韓民國). Today, the Republic of China (中華民國) and Republic of Korea (大韓民國) are unique in the choice of the term 民國 ('people's country') as an equivalent to "republic" in other languages.
The country was in English known at the time as "the Republic of China" or simply "China".
In China today, the period from 1912 to 1949 is often called the "Republican Era" (simplified Chinese: 民国时期; traditional Chinese: 民國時期), because from the Chinese government's perspective the ROC ceased to exist in 1949. In Taiwan, these years are called the "Mainland period" (大陸時期; 大陆时期), since it was when the ROC was based on the mainland.
A republic was formally established on 1 January 1912 following the Xinhai Revolution, which itself began with the Wuchang uprising on 10 October 1911, successfully overthrowing the Qing dynasty and ending over two thousand years of imperial rule in China. From its founding until 1949, the republic was based on mainland China. Central authority waxed and waned in response to warlordism (1915–1928), a Japanese invasion (1937–1945), and a full-scale civil war (1927–1949), with central authority strongest during the Nanjing Decade (1927–1937), when most of China came under the control of the authoritarian, one-party military dictatorship of the nationalist Kuomintang party (KMT). Neither the Nanjing government nor the earlier Beiyang government succeeded in consolidating governance in rural China.
In 1945, at the end of World War II, the Empire of Japan surrendered control of Taiwan and its island groups to the Allies; and Taiwan was placed under the Republic of China's administrative control. The communist takeover of mainland China in 1949, after the Chinese Civil War, left the ruling Kuomintang with control over only Taiwan, Penghu, Kinmen, Matsu, and other minor islands. With the loss of the mainland, the ROC government retreated to Taiwan and the KMT declared Taipei the provisional capital. Meanwhile, the CCP took over all of mainland China and founded the People's Republic of China (PRC) in Beijing.
In 1912, after over two thousand years of dynastic rule, a republic was established to replace the monarchy. The Qing dynasty that preceded the republic had experienced instability throughout the 19th century and suffered from both internal rebellion and foreign imperialism. A program of institutional reform proved too little and too late. Only the lack of an alternative regime prolonged the monarchy's existence until 1912.
The Chinese Republic grew out of the Wuchang Uprising against the Qing government, on 10 October 1911, which is now celebrated annually as the ROC's national day, also known as "Double Ten Day". Sun Yat-sen had been actively promoting revolution from his bases in exile. He then returned from the United States to China and on 29 December, Sun Yat-sen was elected as the provisional president by the revolutionists' assembly in Nanjing, which consisted of representatives from seventeen provinces. On 1 January 1912, he was formally inaugurated and pledged "to overthrow the despotic government led by the Manchu, consolidate the Republic of China and plan for the welfare of the people". Sun's new government lacked military strength. As a compromise, he negotiated with Yuan Shikai the commander of the Beiyang Army, promising Yuan the presidency of the republic if he were to remove the Qing emperor by force. Yuan agreed to the deal. On 12 February 1912, regent Empress Dowager Longyu signed the abdication decree on behalf of Puyi, ending several millennia of monarchical rule.