The main liberation movement in East Timor, and winner of the recent democratic elections. It is Fretilin and its military wing Falintil that conducted guerrilla operations against the Indonesian invaders for twenty-five years.

After the overthrow of the dictatorship in Portugal in April 1974, its colonies moved towards independence. As Portuguese Timor was a small country almost surrounded by huge Indonesia, integration with Indonesia was an alternative to independence there. Fretilin, or officially FRETILIN, which stands for the Frente Revolucionária do Timor-Leste Independente (Portuguese for Revolutionary Front for Independent East Timor), had been formed in 1974 and favoured independence, but two rival parties favoured, or were brought to favour, integration. One of them, the UDT, staged a coup in August 1975 to foil the result of local elections. Fretilin seized power from the UDT, and on 28 November proclaimed the Democratic Republic of East Timor (DRET).

Indonesia invaded the republic on 7 December and later annexed it: this was never recognized by any country except Australia, which did it in narrow self-interest because of lucrative oil fields in the Timor Sea. (Now that freedom has returned to East Timor, Australia has conceded most of these instead of insisting on a seabed border half way between.)

Fretilin and FALINTIL (Forças Armadas de Libertação Nacional de Timor-Leste) continued to fight Indonesia from the hills. Their president Nicolau dos Reis Lobato was killed in December 1978. Their foreign minister Jose Ramos Horta toured the world getting support for the East Timorese struggle, and their new leader Xanana Gusmao continued to be treated as their leader even through his years of imprisonment and house arrest in Indonesia.

In later years Fretilin formed part of other groupings with its former rival the UDT: the CNRM or Conselho Nacional de Resistência Maubere (National Council for Maubere Resistance), formed in 1987 under Xanana Gusmão; then in 1998 the CNRT or Conselho Nacional de Resistência Timorense (National Council of Timorese Resistance).

In October 1999 East Timor was freed from Indonesian rule and passed under a United Nations mandate. Gusmão returned to lead Fretilin to victory in the August 2001 elections, with 57% of the vote and 55 out of 88 seats.

The international community recognized East Timorese independence on 20 May 2002, but the constitution maintains that the country is the same República Democrática de Timor-Leste that Fretilin proclaimed independent on 18 November 1975.