Fretilin was founded on 20 May 1974, initially known as the Timorese Social Democratic Association (ASDT). ASDT renamed itself Fretilin on 11 September 1974 and took a more radical stance, proclaiming itself the “sole legitimate representative” of the East Timorese people. In response to a coup by the Timorese Democratic Union (UDT) on 11 August 1975, Fretilin hastily formed an armed wing called Falintil, which emerged victorious after a three week civil war. Falintil would continue to wage war against the Indonesian military during its invasion on 7 December 1975 and ensuing occupation.