The islands of Cabo Verde were populated by Portuguese, African slaves, and mixed African-European people during Portuguese rule. They spoke Portuguese or Crioulo and were mostly Catholics. In 1956, nationalists from Cabo Verde and Portuguese Guinea formed a party for independence. In the 1960s, they successfully fought for independence through guerrilla warfare. Cabo Verde gained independence on July 5, 1975, and was ruled by the party that led the fight for independence.