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.
James Long (filibuster)
By June 1819, the so-called Long Expedition had arrived in Texas and successfully captured Nacogdoches. His followers proclaimed Long the first president of the new "Republic of Texas" (unrelated to the later Republic of Texas that was the result of the Texas Revolution), also called the "Long Republic". Despite this initial success, Long's independent republic lasted just four months. His army eventually grew restless and many men returned to the United States, and a Spanish expedition routed Long and his remaining followers in October 1819. Long escaped to Natchitoches, Louisiana.