 By the 1950s the Congo had a wage labour force twice as large as that in any other African colony.In 1960, as the result of a widespread and increasingly radical pro-independence movement, the Congo achieved independence, becoming the Republic of Congo under Prime Minister Patrice Lumumba and President Joseph Kasa-Vubu.Poor relations between political factions within the Congo, the continued involvement of Belgium in Congolese affairs, and the intervention by major parties (mainly the United States and the Soviet Union) during the Cold War led to a five-year-long period of war and political instability, known as the Congo Crisis, from 1960 to 1965.