Southern Sudan voted overwhelmingly for independence from Sudan in January 2011. It was confirmed that nearly 99% of the voters in the referendum were in favour of dividing Africa's biggest country. The formal declaration of independence was made on 9 July 2011 - six years after the peace deal, which led to the referendum, took effect.
The above map shows that the great divide across Sudan is visible even from space, as this Nasa satellite image shows. The northern states are a blanket of desert, broken only by the fertile Nile corridor. Southern Sudan is covered by green swathes of grassland, swamps and tropical forest.
Source: BBC News
South Sudan is in east central Africa with a land area of over 0.6 million km2 and an estimated population of 12 million. The capital city is Juba. It is dominated by the River Nile and borders the Central African Republic, Ethiopia, Kenya, Sudan, Uganda and the Democratic Republic of the Congo. It is a landlocked country and Its land borders total 5,431 km. The climate is hot with seasonal rainfall influenced by the annual shift of the Inter-Tropical Convergence Zone; rainfall is heaviest in the upland areas of the south and diminishes to the north. The terrain gradually rises from plains in the north and centre to southern highlands along the border with Uganda and Kenya; the White Nile, flowing north out of the uplands of Central Africa, is the major geographic feature of the country supporting agriculture and extensive wild animal populations.
The Sudd is a vast swamp in South Sudan, formed by the White Nile, comprising more than 15% of the total area of the country; it is one of the world's largest wetlands. Its name is derived from floating vegetation that hinders navigation. The land elevation is from sea level to the highest point Kinyeti at 3,187 m close to the Uganda border.
The official language is Arabic and some English is spoken. More details can be found at CIA Factbook.