Timor Island was first colonised by the Portuguese in 1515. The Dutch, who claimed many of the surrounding islands, took control of the western portion of the island in 1613. Portugal and the Netherlands fought over the island until an 1859 treaty divided Timor, granting Portugal the eastern half of the island as well as the enclave of Oecussi (the first Portuguese settlement on the island). Australia and Japan fought each other on the island during World War II where nearly 60,000 East Timorese died during the subsequent Japanese occupation.

In 1949, the Netherlands gave up its colonies in the Dutch East Indies, including West Timor, and the nation of Indonesia was born. Timor-Leste remained under Portuguese control until 1975, when the Portuguese abruptly pulled out after 460 years of colonization following the change of government in Portugal in the wake of the Carnation Revolution. The sudden Portuguese withdrawal left the island vulnerable. On November 28, 1975, the East Timorese FRETILIN party unilaterally declared independence from Portugal. The Democratic Republic of Timor-Leste (RDTL) was born. On December 7, 1975. Nine days later, it was invaded and occupied by Indonesian forces before the declaration could be internationally recognized. The territory was declared the 27th province of Indonesia in July 1976 despite the UN Security Council’s unanimous vote for Indonesia to stop its invasion and to withdraw immediately from Timor-Leste’s borders. Its nominal status in the UN remained that of a “non-self-governing territory under Portuguese administration. Over 250,000 people, one third of the population of 1975, lost their lives in conflict-related deaths in the period between 1974-1999. Following a UN-sponsored agreement between Indonesia, Portugal and the United States and a surprise decision by the Indonesian President B. J. Habibie, a UN-supervised popular referendum was held on August 30, 1999 to choose between Special Autonomy within Indonesia and independence. A 78.5% of voters chose independence, which resulted in violent clashes, instigated primarily by elements within the Indonesian military and aided by Timorese pro-Indonesia militia. Shortly after, a punitive scorched-earth campaign commenced. The militias killed approximately 1,400 Timorese and forcibly pushed 300,000 people into West Timor as refugees and destroyed 85% of the country’s infrastructure. On 20 September 1999, an International Force for East Timor (INTERFET), led by Australia, was deployed to the country and brought the violence to an end. Following a United Nations-Administered Transition (UNTAET) period. On May 20, 2002, the independence of Timor-Leste was restored, and power was handed from the United Nations to the first Constitutional Government of the Democratic Republic of Timor-Leste.