1. South Sudan gained independence from Sudan on 9 July 2011 as the outcome of a 2005 peace deal that ended Africa's longest- running civil war. An overwhelming majority of South Sudanese voted in a January 2011 referendum to secede and become Africa's first new country since Eritrea split from Ethiopia in 1993. The new nation stands to benefit from inheriting the bulk of Sudan's oil wealth, but continuing disputes with Khartoum and a lack of economic development cloud its immediate future. The larger north is Arab, Muslim and determined to impose Islamic sharia law. The south is black, Christian and animist, with a long history of ethnic persecution by the north.

3. Formed from the 10 southern-most states of Sudan, South Sudan is a land of expansive grassland, swamps and tropical rain forest straddling both banks of the White Nile. It is highly diverse ethnically and linguistically. Among the largest ethnic groups are the Dinka, Nuer and Shilluk. Unlike the predominantly Muslim population of Sudan, the South Sudanese follow traditional religions, while a minority are Christians.

7. As Sudan prepared to gain independence from joint British and Egyptian rule in 1956, southern leaders accused the new authorities in Khartoum of backing out of promises to create a federal system, and of trying to impose an Islamic and Arabic identity. In 1955, southern army officers mutinied, sparking off a civil war between the south, led by the Anya Nya guerrilla movement, and the Sudanese government. The yes vote in the 2011 referendum on independence sparked scenes of jubilation The conflict only ended when the Addis Ababa peace agreement of 1972 accorded the south a measure of autonomy.

8. But, in 1983, the south, led by the Sudan People's Liberation Movement (SPLM) and its armed wing, the Sudan People's Liberation Army (SPLA), again rose in rebellion when the Sudanese government cancelled the autonomy arrangements. At least 1.5 million people are thought to have lost their lives and more than four million were displaced in the ensuing 22 years of guerrilla warfare. Large numbers of South Sudanese fled the fighting, either to the north or to neighbouring countries, where many remain. The conflict finally ended with the 2005 Comprehensive Peace Agreement, under which the south was granted regional autonomy along with guaranteed representation in a national power-sharing government. The agreement also provided for a referendum in the south on independence in 2011, in which 99% of southern Sudanese voted to split from Sudan.

15. Race, Religion, and Resources Sudan, which is a quarter the size of the United States but home to just 44 million people, was ravaged by civil war even before it gained independence from Britain in 1956. Decades of fighting followed with every horror imaginable. Sudan has a powerful northern government of Arab Muslims who were pitted against blacks in Southern Sudan who practice Christianity and animist religions. Africa meets Arabia in this vast land, and the two halves of the nation differ in culture, race and religion. Over two centuries, the Arab north oppressed the African south, raiding it for slaves well into the 20th century. Sudan's two long civil wars since its independence from Anglo-Egyptian control in 1956 have claimed some 2 million lives.

16. What was the root cause of the conflict? Southerners rebelled in 1955 against what they saw as domination from the north as the country neared independence. Nearly all jobs in the new national government went to northerners. The northern government later sought to impose sharia, or Islamic law, on the non-Muslim south. That further polarized the two sides. The war has had overtones of religious and racial conflict, but it's also a fight for power. One scholar has described it as a "clash of identities in competition over power and resources." The north-south conflict is separate from violence in the western Sudanese region of Darfur, which has undergone its own tentative peace process.