Sudan's civil war, which raged from the 1980s until a peace deal was brokered in the early 2000s, marks the longest war ever to take place on the African continent. Dr. Hassan al-Turabi, who served as intellectual mentor of the Sudanese regime for much of the war, states that "We have never known slavery," although many in the south claimed that the North launched regular slave raids into their territory. "There were times when the situation seemed quite hopeless," remarks Nhial Deng, former SPLM Secretary of Foreign Affairs, on the fitful negotiations that finally led to a peace treaty in 2005.