Sudan is the third-largest oil producer in sub-Saharan Africa, behind Nigeria and Angola. Last year it produced 490,000 barrels of oil a day. Most of the oil is in the south, but the pipelines run through the north.

In 2005 the north and south signed a peace accord, ending a civil war that spanned more than two decades. About two million people died in the conflict.

Below are key dates in the history of Sudan:

Source: Al Jazeera and agencies