In the 16th Century, Portuguese interest in the region focused on the slave trade to supply the needs of its newfound colony, Brazil Portuguese influence remained centered around Luanda (founded in 1575) and the kingdom of Ndongo ruled by chiefs referred to as ngola- which eventually served as an inspiration when naming independent Angola. It was not until the 1920s that Portugal managed to extend its influence to the borders of Angola, as defined by European treaties in the 1880s and 1890s. A protracted anti-colonial insurgent war ended in when Portugal granted independence to Angola in 1974 after army officers toppled the Salazar regime in Lisbon. Three movements were involved in the freedom struggle, largely divided on a regional and ethnic basis: The Popular Movement for the Liberation of Angola (MPLA) (receiving support from Cuba and the Soviet Union), the National Front for the Liberation of Angola (FNLA) and the National Union for the Total Independence of Angola (UNITA) (receiving assistance from the US and leader Agostinho Neto was sworn in as the first president of an independent Angola under Marxist one-party rule. Both FNLA and UNITA turned their offensive against the new rulers. Even though US backing and South African support were eventually withdrawn, UNITA leader Jonas Savimbi continued the war. Dr. Neto died in 1979 and was succeeded as president by the new leader of the MPLA, José Eduardo dos Santos. The next election was scheduled for 2006, but has been delayed.