Despite its ostensibly obvious contradictions, lusotropicalism was widely accepted among the people of Portugal until the mid-1970s, and was used by the government to justify its continued involvement in Africa during a period when most European powers were leaving or had already left the continent.  These colonial policies of the twentieth century instigated the forty years of conflict in Angola.  However, a long history of violence and exploitation created the context for these struggles, starting with the Atlantic slave trade in the late fifteenth century. 