Republic of Formosa
The Republic of Formosa (), was a short-lived republic that existed on the island of Taiwan in 1895 between the formal cession of Taiwan by the Qing Dynasty of China to the Empire of Japan by the Treaty of Shimonoseki and it being taken over by Japanese troops. The Republic was proclaimed on 23 May 1895 and extinguished on 21 October, when the Republican capital Tainan was taken over by the Japanese. Though sometimes claimed as the first Asian republic to have been proclaimed, it was predated by the Lanfang Republic in Borneo, established in 1777, as well as by the Republic of Ezo in Japan, established in 1869.
Second Sino-Japanese War
Formosa and the Penghu islands were put under the administrative control of the Republic of China (ROC) government in 1945 by the United Nations Relief and Rehabilitation Administration. The ROC proclaimed Taiwan Retrocession Day on October 25, 1945. However, due to the unresolved Chinese Civil War, neither the newly established People's Republic of China (PRC) in mainland China nor the Nationalist ROC that retreated to Taiwan was invited to sign the Treaty of San Francisco, as neither had shown full and complete legal capacity to enter into an international legally binding agreement. Since China was not present, the Japanese only formally renounced the territorial sovereignty of Taiwan and Penghu islands without specifying to which country Japan relinquished the sovereignty, and the treaty was signed in 1951 and came into force in 1952.