Since the Angolan War of Independence from Portugal in 1975, Angola has had three constitutions. The first came into force in 1975 as an "interim" measure; the second was approved in a 1992 referendum, and the third one was instituted in 2010.
Angola was a colony of Portugal for more than 400 years, beginning the 15th century. Three principal parties, MPLA, National Front for the Liberation of Angola (FNLA) and the National Union for Total Independence of Angola (UNITA), fought for independence. After many years of conflict that weakened all of the insurgent parties, Angola gained independence on 11 November 1975, after the Carnation Revolution overthrew the Marcelo Caetano regime in Portugal.