A chronology of key events:
1881 - Revolt against the Turco-Egyptian administration.
1899-1955 - Sudan is under joint British-Egyptian rule.
1956 - Sudan becomes independent.
1958 - General Abboud leads military coup against the civilian government elected earlier in the year
1962 - Civil war begins in the south, led by the Anya Nya movement.
1964 - The "October Revolution" overthrows Abbud and an Islamist-led government is established
1969 - Jaafar Numeiri leads the "May Revolution" military coup.
1971 - Sudanese Communist Party leaders executed after short-lived coup against Numeiry.
1972 - Under the Addis Ababa peace agreement between the government and the Anya Nya, the south becomes a self-governing region.
1978 - Oil discovered in Bentiu in southern Sudan.
1983 - Civil war breaks out again in the south involving government forces and the Sudan People's Liberation Movement (SPLM), led by John Garang.Islamic law imposed
1983 - President Numeiri declares the introduction of Sharia Islamic law.
1985 - After widespread popular unrest Numayri is deposed by a group of officers and a Transitional Military Council is set up to rule the country.
1986 - Coalition government formed after general elections, with Sadiq al-Mahdi as prime minister.
1988 - Coalition partner the Democratic Unionist Party drafts cease-fire agreement with the SPLM, but it is not implemented.
1989 - National Salvation Revolution takes over in military coup.
1993 - Revolution Command Council dissolved after Omar Bashir is appointed president.US strike
1995 - Egyptian President Mubarak accuses Sudan of being involved in attempt to assassinate him in Addis Ababa.
1998 - US launches missile attack on a pharmaceutical plant in Khartoum, alleging that it was making materials for chemical weapons.
1998 - New constitution endorsed by over 96% of voters in referendum.
1999 - President Bashir dissolves the National Assembly and declares a state of emergency following a power struggle with parliamentary speaker, Hassan al-Turabi.Advent of oil
1999 - Sudan begins to export oil.
2000 President Bashir meets leaders of opposition National Democratic Alliance for first time in Eritrea.
Main opposition parties boycott presidential elections. Incumbent Bashir is re-elected for further five years.
2001 Islamist leader 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). Al-Turabi is arrested the next day, with more arrests of PNC members in the following months.
US extends unilateral sanctions against Sudan for another year, citing its record on terrorism and rights violations.Peace deal
2002 - Government and SPLA sign landmark ceasefire agreement providing for six-month renewable ceasefire in central Nuba Mountains - a key rebel stronghold.
Talks in Kenya lead to a breakthrough agreement between the government and southern rebels on ending the 19-year civil war. The Machakos Protocol provides for the south to seek self-determination after six years.
2003 February - Rebels in western region of Darfur rise up against government, claiming the region is being neglected by Khartoum.
2003 October - PNC leader Turabi released after nearly three years in detention and ban on his party is lifted.Uprising in west
2004 January - Army moves to quell rebel uprising in western region of Darfur; hundreds of thousands of refugees flee to neighbouring Chad.
2004 March - UN official says pro-government Arab Janjaweed militias are carrying out systematic killings of non-Arab villagers in Darfur.
Army officers and opposition politicians, including Islamist leader Hassan al-Turabi, are detained over an alleged coup plot.
2004 September - UN says Sudan has not met targets for disarming pro-government Darfur militias and must accept outside help to protect civilians. US Secretary of State Colin Powell describes Darfur killings as genocide.Peace agreement
2005 January - Government and southern rebels sign a peace deal. The agreement includes a permanent ceasefire and accords on wealth and power sharing.
UN report accuses the government and militias of systematic abuses in Darfur, but stops short of calling the violence genocide.
2005 March - UN Security Council authorises sanctions against those who violate ceasefire in Darfur. Council also votes to refer those accused of war crimes in Darfur to International Criminal Court.
2005 June - Government and exiled opposition grouping - National Democratic Alliance (NDA) - sign reconciliation deal allowing NDA into power-sharing administration.
President Bashir frees Islamist leader Hassan al-Turabi, detained since March 2004 over alleged coup plot.Southern autonomy
2005 9 July - Former southern rebel leader John Garang is sworn in as first vice president. A constitution which gives a large degree of autonomy to the south is signed.
2005 1 August - Vice president and former rebel leader John Garang is killed in a plane crash. He is succeeded by Salva Kiir. Garang's death sparks deadly clashes in the capital between southern Sudanese and northern Arabs.
2005 September - Power-sharing government is formed in Khartoum.
2005 October - Autonomous government is formed in the south, in line with January 2005 peace deal. The administration is dominated by former rebels.Darfur conflict
2006 May - Khartoum government and the main rebel faction in Darfur, the Sudan Liberation Movement, sign a peace accord. Two smaller rebel groups reject the deal. Fighting continues.
2006 August - Sudan rejects a UN resolution calling for a UN peacekeeping force in Darfur, saying it would compromise sovereignty.
2006 October - Jan Pronk, the UN's top official in Sudan, is expelled.
2006 November - African Union extends mandate of its peacekeeping force in Darfur for six months.
Hundreds are thought to have died in the heaviest fighting between northern Sudanese forces and their former southern rebel foes since they signed a peace deal last year. Fighting is centred on the southern town of Malakal.
2007 April - Sudan says it will accept a partial UN troop deployment to reinforce African Union peacekeepers in Darfur, but not a full 20,000-strong force.War crimes charges
2007 May - International Criminal Court issues arrest warrants for a minister and a Janjaweed militia leader suspected of Darfur war crimes.
US President George W Bush announces fresh sanctions against Sudan.
2007 July - UN Security Council approves a resolution authorising a 26,000-strong force for Darfur. Sudan says it will co-operate with the United Nations-African Union Mission in Darfur (Unamid).
2007 October - SPLM temporarily suspends participation in national unity government, accusing Khartoum of failing to honour the 2005 peace deal. Returns to government in December.
2008 January - UN takes over Darfur peace force. Government planes bomb rebel positions in West Darfur, turning some areas into no-go zones for aid workers.Abyei clashes
2008 March - Presidents of Sudan and Chad sign accord aimed at halting five years of hostilities between their countries.
2008 April - Counting begins in national census which is seen as a vital step towards holding democratic elections after the landmark 2005 north-south peace deal.
UN humanitarian chief John Holmes says 300,000 people may have died in the five-year Darfur conflict.
2008 May - Southern defence minister Dominic Dim Deng is killed in a plane crash in the south.
Tension increases between Sudan and Chad after Darfur rebel group mounts raid on Omdurman, Khartoum's twin city across the Nile. Sudan accuses Chad of involvement and breaks off diplomatic relations.
Intense fighting breaks out between northern and southern forces in disputed oil-rich town of Abyei.
2008 June - President Bashir and southern leader Salva Kiir agree to seek international arbitration to resolve dispute over Abyei.Bashir accused
2008 July - The International Criminal Court's top prosecutor calls for the arrest of President Bashir for genocide, crimes against humanity and war crimes in Darfur; the appeal is the first ever request to the ICC for the arrest of a sitting head of state. Sudan rejects the indictment.
2008 November - President Bashir announces an immediate ceasefire in Darfur, but the region's two main rebel groups reject the move, saying they will fight on until the government agrees to share power and wealth in the region.
2009 January - Sudanese Islamist leader Hassan al-Turabi is arrested after saying President Bashir should hand himself in to The Hague to face war crimes charges for the Darfur war.
2009 March - The International Criminal Court in The Hague issues an arrest warrant for President Bashir on charges of war crimes and crimes against humanity in Darfur.Alliance strained
2009 June - Khartoum government denies it is supplying arms to ethnic groups in the south to destabilise the region.
Hassan Abdallah al-Turabi has been prominent in promoting Islamic law in Sudan
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 August - Darfur war is over, says UN military commander in the region, in comments condemned by activists.
2009 December - Leaders of North and South reach deal on terms of referendum on independence due in South by 2011.Darfur deal
2010 Feb-March - The Justice and Equality Movement (Jem) main Darfur rebel movement signs a peace accord with the government, prompting President Bashir to declare the Darfur war over. But failure to agree specifics and continuing clashes with smaller rebel groups endanger the deal.
2010 April - President Bashir gains new term in first contested presidential polls since 1986.
2010 July - International Criminal Court issues second arrest warrant for President al-Bashir - this time on charges of genocide.
2010 August - Mr Bashir tests ICC arrest warrant by visiting Kenya, an ICC signatory. The Kenyan government refuses to enforce the warrant.
2011 January - People of the South vote in favour of full independence from the north.
2011 May - Northern troops overrun town of Abyei on disputed border between north and south. South describes it as ''act of war''. Thousands flee.South becomes independent
2011 July - South Sudan gains independence.
2011 September - State of emergency declared in Blue Nile state, elected SPLM-N Governor Malik Agar sacked. Some 100,000 said fleeing unrest.
2011 October - South Sudan and Sudan agree to set up several committees tasked with resolving their outstanding disputes.
2011 November - Sudan accused of bombing refugee camp in Yida, Unity State, South Sudan.
A Kenyan judge issues an arrest warrant for President Bashir, saying he should be detained if ever he sets foot in the country again.
2011 December - International Criminal Court's chief prosecutor requests arrest warrant for Sudan's defence minister, Abdelrahim Mohamed Hussein, for alleged war crimes in Darfur.
Sudanese government forces kill key Darfur rebel leader Khalil Ibrahim.
2012 January - South Sudan halts oil production after talks on fees for the export of oil via Sudan break down.
2012 February-April - Sudan and South Sudan sign non-aggression pact at talks on outstanding secession issues, but border fighting breaks out.
2012 May - Sudan pledges to pull its troops out of the border region of Abyei, which is also claimed by South Sudan, as bilateral peace talks resume.Protests
2012 June - Week-long protests in Khartoum at austerity measures spread from students to general public and turn into clashes with police. The government cut fuel and other subsidies because of the drop in oil revenues after the independence of South Sudan.
2012 August - Some 655,000 have been displaced or severely affected by fighting between the army and rebels in states bordering on South Sudan, the UN reports.
Sudan and South Sudan strike a last-minute deal on the South's export of oil via Sudan's pipelines.
2012 September - The presidents of Sudan and South Sudan agree trade, oil and security deals after days of talks in Ethiopia. They plan to set up a demilitarised buffer zone and lay the grounds for oil sales to resume. They fail however to resolve border issues including the disputed Abyei territory.
Clashes with rebels in Darfur and South Kordofan region.
2012 October - Explosions destroy an arms factory in Khartoum. Sudan accuses Israel of the attack on what is believed to be an Iranian-run plant making weapons for Hamas in Gaza. Israel declines to comment.
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 - Dozens killed in fighting between two Arab tribes vying for control of a gold mine in Darfur. An initial bout of violence, in January, killed around 500 people.
2013 September - Wave of demonstrations across the country over the government's decision to cut fuel subsidies. Scores die in clashes with police.Ruling party splits
2013 October - Following allegations of corruption and stagnant leadership within the ruling National Congress Party (NCP), more than 30 dissident NCP members announce plans to form a breakaway party that they say will reach out to secularists and leftists in a bid to create a more inclusive democracy. It is seen as the most serious split in the ruling elite since Hassan al-Turabi fell out with President Bashir in 1999.
2013 December - President Bashir carries out a major shake-up of his cabinet, dropping stalwarts such as his long-time first vice president Ali Osman Taha - a key figure in the coup that brought Mr Bashir to power in 1989 - and bringing in some new faces.