After the Carnation Revolution of 1974, Portugal acknowledged that under Chapter XI of the Charter of the United Nations its overseas possessions had the right to gain independence. A National Decolonisation Commission was established to begin consultations with East Timor in 1975. Before negotiations were completed, the political party Timorese Democratic Union attempted a Coup d'état and a brief civil war ensued. Fretilin emerged victorious and declared the independence of East Timor on 28 November 1975. On 7 December 1975, Indonesia invaded East Timor. Portugal notified the United Nations (UN) of the invasion and immediately severed diplomatic relations with Indonesia. The United Nations Security Council issued a resolution in 1976 calling for the immediate withdrawal of Indonesian troops and reaffirming East Timor's right to self-determination. Disregarding the UN, Indonesia formally annexed the territory in July.