Chinese unification, also known as Cross-Strait unification or Chinese reunification, is the potential unification of territories currently controlled, or claimed, by the People's Republic of China ("China" or "Mainland China") and the Republic of China ("Taiwan") under one political entity, possibly the formation of a political union between the two republics. Together with full Taiwan independence, unification is one of the main proposals to address questions on the political status of Taiwan, which is a central focus of Cross-Strait relations.
In the year 1895, the Manchu Qing dynasty of China lost the First Sino-Japanese War and was forced to cede Taiwan and Penghu to the Empire of Japan after signing the Treaty of Shimonoseki. In 1912, the Qing dynasty was overthrown and was succeeded by the Republic of China (ROC). Based on the theory of the succession of states, the ROC originally lay claim to the entire territory which belonged to the Qing dynasty during the time of its collapse, except for Taiwan, which the ROC recognized as belonging to the Empire of Japan at the time. The ROC managed to attain widespread recognition as the legitimate successor state to the Qing dynasty during the years following the fall of the Qing dynasty.
In the year 1945, the ROC won the Second Sino-Japanese War, which was intertwined with World War II, and took control of Taiwan on behalf of the Allied Powers, following the Japanese surrender. The ROC immediately asserted its claim to Taiwan as "Taiwan Province, Republic of China", basing its claim on the Potsdam Declaration and the Cairo Communique. Around this time, the ROC nullified the Treaty of Shimonoseki, declaring it to be one of the many "Unequal Treaties" imposed on China during the so-called "Century of Humiliation". At the time, the Kuomintang (KMT) was the ruling party of the ROC, and was widely recognized as its legitimate representative, especially due to the collaboration of its leader Chiang Kai-shek with the Allied Powers.