Sudan country profile
Sudan, once the largest and one of the most geographically diverse states in Africa, split into two countries in July 2011 after the people of the south voted for independence.
The government of Sudan gave its blessing for an independent South Sudan, where the mainly Christian and Animist people had for decades been struggling against rule by the Arab Muslim north.
However, various outstanding issues - especially the question of shared oil revenues and border demarcation - have continued to create tensions between the two successor states.
Sudan has long been beset by conflict. Two rounds of north-south civil war cost the lives of 1.5 million people, and a continuing conflict in the western region of Darfur has driven two million people from their homes and killed more than 200,000.
Republic of Sudan
Population 45.7 million
Major languages Arabic, English(official)
Major religion Islam
Life expectancy 60 years (men), 64 years (women)
Currency Sudanese pound
President: Omar Hassan al-Bashir
Omar Hassan al-Bashir has ruled with an iron fist for more than 25 years.
He come to power in a coup in 1989 and was elected president in 1996.
He was re-elected several times since, most recently in 2015 when he gained another five-year term. Most opposition parties boycotted the vote.
Mr Bashir faces two international arrest warrants - issued by the International Criminal Court in The Hague - on charges of genocide, war crimes and crimes against humanity.
Sudanese broadcasting is highly restricted and state TV and radio reflect government policy.
The private press carries opposition views, but the state uses its powers to influence what is published.
Sudan had 9.3 million internet users by July 2014, with blogging being subject to scrutiny.
Some key dates in Sudan's history:
Circa 2000-1500 BC - Emergence of the Nubian Kingdom of Kush in what is now northern Sudan and Lower Nubia, which stretches to Egypt's Aswan province.
651 - Islam spreads in Sudan from Egypt.
1820-21 - Ottoman Empire conquers northern part of the country.
1899-1955 - Sudan is under joint British-Egyptian rule.
1956 - Sudan becomes independent.
1983 - President Numeiri introduces Sharia Islamic law.
2003 - Start of conflict in Darfur region.
2009 - International Criminal Court issues an arrest warrant for President Omar Bashir on charges of war crimes and crimes against humanity relating to the drawn-out conflict in Darfur.
2011 - South Sudan gains independence following years of war with the central government in Khartoum.