Map of East Timor and its major cities
Portuguese first arrived in
Timor in the 16th century, and in 1702 East Timor came under
Portuguese colonial administration.
 Portuguese rule was tenuous until the island was divided with the
Dutch Empire in 1860.
 A significant battleground during the
Pacific War, East Timor was
occupied by 20,000 Japanese troops. The fighting helped prevent a Japanese occupation of Australia, but resulted in 60,000 East Timorese deaths.
secured its independence after World War II under the leadership of
Sukarno, it did not claim control of East Timor, and aside from general anti-colonial rhetoric it did not oppose Portuguese control of the territory. A 1959 revolt in East Timor against the Portuguese was not endorsed by the Indonesian government.
 A 1962 United Nations document notes: "the government of Indonesia has declared that it maintains friendly relations with Portugal and has no claim to Portuguese Timor...".
 These assurances continued after
Suharto took power in 1965. An Indonesian official declared in December 1974: "Indonesia has no territorial ambition ... Thus there is no question of Indonesia wishing to annex Portuguese Timor."
In 1974, a
coup in Lisbon caused significant changes in Portugal's relationship to its colony in Timor.
 The power shift in Europe invigorated movements for independence in colonies like Mozambique and Angola, and the new Portuguese government began a decolonisation process for East Timor. The first of these was an opening of the political process.
Fretilin, UDT, and APODETI
When East Timorese political parties were first legalised in April 1974, three groupings emerged as major players in the postcolonial landscape. The União Democrática Timorense (
Timorese Democratic Union, or UDT), was formed in May by a group of wealthy landowners. Initially dedicated to preserving East Timor as a protectorate of Portugal, in September UDT announced its support for independence.
 A week later, the Frente Revolucionária de Timor-Leste Independente (
Revolutionary Front for an Independent East Timor, or Fretilin) appeared. Initially organised as the
ASDT (Associacão Social Democrata Timorense), the group endorsed "the universal doctrines of socialism", as well as "the right to independence".
 As the political process grew more tense, however, the group changed its name and declared itself "the only legitimate representative of the people".
 The end of May saw the creation of a third party, Associacão Popular Democratica Timorense (
Timorese Popular Democratic Association, or APODETI). Advocating East Timor's integration with Indonesia and originally named Associacão Integraciacao de Timor Indonesia (Association for the Integration of Timor into Indonesia),
 APODETI expressed concerns that an independent East Timor would then be economically weak and vulnerable.
took power after the civil war and declared an independent East Timor on 28 November 1975.
Indonesian nationalist and military hardliners, particularly leaders of the intelligence agency
Kopkamtib and special operations unit,
Opsus, saw the Portuguese coup as an opportunity for East Timor's integration with Indonesia. The central government and military feared that an East Timor governed by
leftists could be used as a base for incursions by unfriendly powers into Indonesia, and also that an independent East Timor within the archipelago could inspire
secessionist sentiments within Indonesian provinces. The fear of national disintegration were played upon military leaders close to Suharto and remained as one of Indonesia's strongest justifications for refusing to entertain the prospect of East Timorese independence or even autonomy until the late 1990s.
 The military intelligence organisations initially sought a non-military
annexation strategy, intending to use APODETI as its integration vehicle.
In January 1975, UDT and Fretilin established a tentative coalition dedicated to achieving independence for East Timor.
 At the same time, the Australian government reported that the
Indonesian military had conducted a "pre-invasion" exercise at
 For months, the Indonesian Special Operations command, OPSUS, had been covertly supporting APODETI through Operasi Komodo (Operation Komodo, named after
the lizard). By broadcasting accusations of communism among Fretilin leaders and sowing discord in the UDT coalition, the Indonesian government fostered instability in East Timor and, observers said, created a pretext for invading.
 By May tensions between the two groups caused UDT to withdraw from the coalition.
In an attempt to negotiate a settlement to the dispute over East Timor's future, the
Portuguese Decolonization Commission convened a conference in June 1975 in
Macau. Fretilin boycotted the meeting in protest of APODETI's presence; representatives of UDT and APODETI complained that this was an effort to obstruct the decolonisation process.
 In his 1987 memoir Funu: The Unfinished Saga of East Timor, Fretilin leader
José Ramos-Horta recalls his "vehement protests" against his party's refusal to attend the meeting. "This", he writes, "was one of our tactical political errors for which I could never find an intelligent explanation."
Coup, civil war, and independence declaration
The tension reached a boiling point in mid-1975, when rumours began circulating of possible power seizures from both independence parties.
 In August 1975, UDT staged a coup in the capital city
Dili and a small-scale civil war broke out. Ramos-Horta describes the fighting as "bloody", and details violence committed by both UDT and Fretilin. He cites the
International Committee of the Red Cross, which counted 2,000–3,000 people dead after the war.
 The fighting forced the Portuguese government onto the nearby island of
 Fretilin defeated UDT's forces after two weeks, much to the surprise of Portugal and Indonesia.
 UDT leaders fled to Indonesian-controlled West Timor. There they signed a petition on 7 September calling for East Timor's integration with Indonesia;
 most accounts indicate that UDT's support for this position was forced by Indonesia.
Map of East Timor's
, which lies on the border with Indonesian
. Fighting continued in this region after the civil war, and several cities were captured by Indonesia prior to their full invasion.
Once they had gained control of East Timor, Fretilin faced attacks from the west, by
Indonesian military forces—then known as Angkatan Bersenjata Republik Indonesia (ABRI)—and by a small group of UDT troops.
 Indonesia captured the border city of Batugadé on 8 October 1975; nearby
Maliana were taken eight days later.
 During the Balibó raid, members of an Australian television news crew—later dubbed the "
Balibo Five"—were killed by Indonesian soldiers.
 Indonesian military officials say the deaths were accidental, and East Timorese witnesses say the journalists were deliberately killed. The deaths, and subsequent campaigns and investigations, attracted international attention and rallied support for East Timorese independence.
At the start of November, the
foreign ministers from Indonesia and Portugal met in Rome to discuss a resolution of the conflict. Although no Timorese leaders were invited to the talks, Fretilin sent a message expressing their desire to work with Portugal. The meeting ended with both parties agreeing that Portugal would meet with political leaders in East Timor, but the talks never took place.
 In mid-November, Indonesian forces began shelling the city of
Atabae from the sea, and captured it by the end of the month.
Frustrated by Portugal's inaction, Fretilin leaders believed they could ward off Indonesian advances more effectively if they declared an independent East Timor. National Political Commissioner
Mari Alkatiri conducted a diplomatic tour of Africa, gathering support from governments there and elsewhere.
According to Fretilin, this effort yielded assurances from twenty-five countries—including the People's Republic of China, the
Soviet Union, Mozambique, Sweden, and Cuba—to recognise the new nation. Cuba currently shares close relations with East Timor today. On 28 November 1975, Fretilin unilaterally
declared independence for the Democratic Republic of East Timor.
 Indonesia announced, UDT and APODETI leaders in and around Balibó would respond the next day by declaring that region independent from East Timor and officially part of Indonesia. But this Balibo Declaration was drafted by Indonesian intelligence and signed on
Bali. Later this was described as the 'Balibohong Declaration', a pun on the Indonesian word for 'lie'.
 Portugal rejected both declarations, and the Indonesian government approved military action to begin its annexation of East Timor.