Independent since 2011, the world’s newest country became engulfed by civil war in 2013 after President Salva Kiir accused his rival and former deputy Riek Machar of plotting a coup against him.
The conflict has left tens of thousands dead and nearly four million displaced — out of a population of around 12 million.
Five things to know about the new African nation:
Economy in ruins
Oil production — from which South Sudan gained 98 percent of its revenues on its independence seven years ago — has plummeted as the war has damaged infrastructure.
Production has dropped to around 120,000 barrels per day compared with 350,000 bpd before the conflict, according to the World Bank.
Juba, which upon independence inherited three quarters of Sudan’s oil reserves, depends on its northern neighbour’s oil infrastructure — refineries and pipelines — for its exports.
In 2017, part of the country suffered four months of famine, affecting around 100,000 people
According to the United Nations, seven million South Sudanese, more than half the population, are in need of humanitarian aid this year.
War against Muslim north
Before South Sudan became independent, it was the southern part of the country of Sudan, which was the scene of two civil wars pitting mainly Christian and animist insurgents in the south against Khartoum’s Muslim Arab-dominated government. Millions died in the conflicts.
Sudan’s independence from Britain and Egypt in January 1956 caused a first war in the south against northern domination.
The accords of 1972 brought an end to 17 years of conflict, and the south was given a measure of autonomy.
But in 1983, Khartoum reneged on the accords, unleashing another war between north and south. That rekindled an independence movement led by John Garang and his guerrilla rebel force, the Sudan People’s Liberation Army (SPLA).
In January 2005, Garang signed a peace accord with Khartoum which exempted the south from Islamic sharia law and granted it six years of self-rule ahead of a referendum on independence.
Garang was killed in a helicopter crash in July 2005 and was succeeded as southern leader by Kiir.
World’s youngest state
On July 9, 2011, South Sudan proclaimed its independence, six months after voting by nearly 99 percent to secede from the north. Kiir was sworn in as the country’s first president.
The international community, led by the United States, China, Russia and the European Union, as well as Sudan, quickly recognised the new African state.
Allies turned enemies
Kiir and his former deputy Machar, were linked by a common cause during the rebellion against Khartoum before independence, but also by ethnic and political rivalries.
During the second Sudanese civil war, Machar, an ethnic Nuer, joined the southern rebel SPLA, which was up to then mainly made up of Kiir’s Dinka tribe. Machar opposed Garang and his allies, including Kiir, and created a rival group which allied itself with Khartoum, before reintegrating the SPLA in the early 2000s.
Kiir nominated him as vice president, first in 2005 in the semi-autonomous South Sudan region, then in July 2011 after the South gained independence.
Then in December 2013, the new country descended into civil war when fighting broke out within the national army, undermined by differences fuelled by the rivalry between Kiir and Machar.
In 2016, the United Nations warned of potential genocide and ethnic cleansing, pointing to sexual and ethnic violence ravaging the country.
An August 2015 peace deal was left in tatters when fighting broke out in Juba in July last year.
On June 20, 2018, Kiir and Machar met in Addis Ababa for the first time in two years. A week later they agreed a ceasefire.
On July 7 in Kampala they reached an accord to share power.
On Sunday, Kiir and Machar signed the accord in Khartoum under which the rebel leader is set to return to a unity government as the first of five vice presidents.
The deal paves the way to a final peace deal, which once signed, will give the foes three months to form a transitional government which will then hold power for three years.