1961 Indian Invasion of Portugal
In 1947, India became independent from Britain, however there were some areas on the Indian continent that were still held as colonies by the Portuguese; Goa, Daman and Diu, and Dadra, and Nagar Haveli. In 1950, the government of India spoke to the Portuguese government about the future of colonies, namely when they might be given their independence to incorporate into India. The Portuguese government responded that those areas were not colonies after all, but actually part of metropolitan Portugal. Therefore, transferring the colonies was not a possibility.
Throughout the 1950s, strife in Goa over the continuation of Portuguese rule increased. A massacre of peaceful Indian activists in 1955 and the Portuguese military firing upon an Indian passenger boat in 1961 (killing one passenger) increased support in India for military action to liberate the Portuguese colonies. In 1954, pro-Indian forces occupied Dadra and Nagar Haveili, two land-locked enclaves that were completely surrounded by Indian land. The Indian government refused to allow the Portuguese military to travel through their lands to put down the occupying forces in their colonies.
In 1961, both India and Portugal knew that armed conflict was on the horizon. Portugal built up their forces in Goa, made a plan for attempting to be a much bigger and stronger military force, and evacuated civilians. On December 11, 1961, Indian forces moved into Goa and both sides fought by land, air, and sea for the fate of the colony.
The United Nations debated and held a vote on December 17, 1961 on whether or not to intervene in a ceasefire, but it was stopped by Soviet Veto. On December 18, 1961, the Portuguese knew that they had lost and officially surrendered the following day. Under the terms of the surrender, Goa, Damon, and Diu were ceded to India.