A chronology of key events
1899-1955 - South Sudan is part of Anglo-Egyptian Sudan, under joint British-Egyptian rule.
1956 - Sudan gains independence.
First civil war
1962 - Civil war led by the southern separatist Anya Nya movement begins with north.
1969 - Group of socialist and communist Sudanese military officers led by Col Jaafar Muhammad Numeiri seizes power; Col Numeiri outlines policy of autonomy for south.
1972 - Government concedes a measure of autonomy for southern Sudan in a peace agreement signed in Addis Ababa.
1978 - Oil discovered in Unity State in southern Sudan.
Second civil war
1983 - Fighting breaks out again between north and south Sudan, under leadership of John Garang's Sudanese People's Liberation Movement (SPLM), after Sudanese President Jaafar Numeiri abolishes South Sudan's autonomy.
1988 - Democratic Unionist Party - part of Sudan's ruling coalition government - drafts cease-fire agreement with the SPLM, but it is not implemented.
1989 - Military seizes power in Sudan.
2001 - Sudanese Islamist leader Hassan Al-Turabi's party, the Popular National Congress, signs memorandum of understanding with the southern rebel SPLM's armed wing, the Sudan People's Liberation Army (SPLA). Mr Al-Turabi is arrested the next day.
2002 - Talks in Kenya lead to a breakthrough agreement between southern rebels and Sudanese government on ending the civil war. The Machakos Protocol provides for the south to seek self-determination after six years.
North-south peace deal
2005 January - North/South Comprehensive Peace Agreement (CPA) ends civil war; deal provides for a permanent ceasefire, autonomy for the south, a power-sharing government involving rebels in Khartoum and a south Sudanese referendum on independence in six years' time.
2005 July - Former southern rebel leader John Garang is sworn in as first vice-president. A new Sudanese constitution which gives the south a large degree of autonomy is signed.
2005 August - South Sudanese leader John Garang is killed in a plane crash. He is succeeded by Salva Kiir Mayardiit.
2005 October - Autonomous government is formed in South Sudan, in line with the January 2005 peace deal. The administration is dominated by former rebels.
2006 November - Hundreds die in fighting centred on the southern town of Malakal - the heaviest between northern Sudanese forces and former rebels since the 2005 peace deal.
2008 March - Tensions rise over clashes between an Arab militia and SPLM in the disputed oil-rich Abyei area on the north-south divide - a key sticking point in the 2005 peace accord.
2009 July - North and south Sudan say they accept ruling by arbitration court in The Hague shrinking disputed Abyei region and placing the major Heglig oil field in the north.
2009 December - Leaders of North and South reach deal on terms of referendum on independence due in South by 2011.
2011 January - The people of South Sudan vote in favour of full independence from Sudan.
2011 February - Clashes between the security forces and rebels in southern Sudan's Jonglei state leave more than 100 dead.
2011 May - North occupies disputed border region of Abyei.
2011 June - Governments of north and south sign accord to demilitarize the disputed Abyei region and let in an Ethiopian peacekeeping force.
New state born
2011 9 July - Independence day.
2011 August - UN says at least 600 people are killed in ethnic clashes in Jonglei state.
2012 January - South Sudan declares a disaster in Jonglei State after some 100,000 flee clashes between rival ethnic groups.
2012 April - After weeks of border fighting, South Sudan troops temporarily occupy the oil field and border town of Heglig before being repulsed. Sudanese warplanes raid the Bentiu area in South Sudan.
2012 August - Some 200,000 refugees flee into South Sudan to escape fighting between Sudanese army and rebels in Sudan's southern border states.
2012 September - The presidents of Sudan and South Sudan agree trade, oil and security deals after days of talks in Ethiopia.
2013 March - Sudan and South Sudan agree to resume pumping oil after a bitter dispute over fees that saw production shut down more than a year earlier. They also agreed to withdraw troops from their border area to create a demilitarised zone.
2013 June - President Kiir dismisses Finance Minister Kosti Manibe and Cabinet Affairs Minister Deng Alor over a multi-million dollar financial scandal, and lifts their immunity from prosecution.
2013 July - President Kiir dismisses entire cabinet and Vice-President Riek Machar in a power struggle within the governing Sudan People's Liberation Movement.
2013 December - Civil war erupts as President Salva Kiir accuses his former vice-president, Riek Machar, of plotting to overthrow him.
Rebel factions seize control of several regional towns, thousands are killed and many more flee. Uganda troops intervene on the government's side.
2014 January - A ceasefire is signed but broken several times over subsequent weeks, and further talks in February fail to end the violence that displaces more than a million people by April.
2014 April - UN says pro-Machar forces sack the oil town of Bentiu, killing hundreds of civilians.
2014 August - Peace talks begin in Ethiopian capital Addis Ababa and drag on for months as fighting continues.
2016 April - Riek Machar finally returns to Juba and is sworn in as first vice-president in a new unity government - but is sacked in July after further conflict and goes back into exile.
2016 November - UN sacks Kenyan commander of its peacekeeping mission over the failure to protect civilians in Juba during July violence. Kenya withdraws its troops from the peacekeeping mission.
Japanese peacekeepers arrive South Sudan, the first time in nearly 70 years that Japan has deployed its soldiers overseas with a broad mandate to use force if necessary.
2016 December - A UN commission on human rights says a process of ethnic cleansing is underway in several parts of the country, a claim that President Salva Kiir denies.
2017 February - A famine is declared in parts of South Sudan in what the UN describes as a man-made catastrophe caused by civil war and economic collapse.
2017 May - President Kiir declares unilateral ceasefire, launches national dialogue.
2017 August - The number of refugees fleeing violence in South Sudan to Uganda passes the one million mark, according to the UN.
2018 August - President Kiir signs power-sharing agreement with Riek Machar and other opposition groups in a bid to end the civil war. The deal will see Machar return to government as one of five vice-presidents.