Yemen profile - Timeline
A chronology of key events:
1500s - Ottomans absorb part of Yemen into their empire, but are expelled in the 1600s.
1839 - Aden comes under British rule, and when the Suez Canal opens in 1869 serves as a major refuelling port.
1849 - Ottomans return to north, but later face revolt.
1918 - Ottoman Empire dissolves, North Yemen gains independence and is ruled by Imam Yahya.
1948 - Yahya assassinated, but his son Ahmad beats off opponents of feudal rule and succeeds his father.
1962 - Imam Ahmad dies and is succeeded by his son, but army officers seize power and set up the Yemen Arab Republic, sparking civil war between royalists supported by Saudi Arabia and republicans backed by Egypt.
South Yemen formed
1967 - Britain withdraws from the south after years of a pro-independence insurgency, and its former territories unite as the People's Republic of Yemen.
1969 - A communist coup renames the south as the People's Democratic Republic of Yemen and reorients it towards the Soviet bloc.
1970 - Republican forces triumph in the North Yemen civil war.
1972 - Border clashes between two Yemens; ceasefire brokered by Arab League.
1978 - Ali Abdallah Saleh becomes president of North Yemen.
1979 - Fresh fighting between the two Yemens. Renewed efforts to unite the two states.
1982 - Earthquake kills about 3,000 people in Dhamar, south of Sanaa.
1986 - Thousands die in power struggle in south, which effectively drives the first generation of leaders from office.
Haidar Abu Bakr al-Attas takes over, and begins to work towards unification of the two states.
1990 May - The two Yemens unite as the Republic of Yemen with Ali Abdallah Saleh as president, as the Soviet bloc implodes. Tension between former states endures.
1994 May-July - President Saleh declares a state of emergency and dismisses Vice-President Ali Salem al-Beid and other southern officials, who declare the secession of the south before being defeated by the national army.
1995 - Yemen and Eritrea clash over the disputed Hanish Islands in the Red Sea. International arbitration awarded the bulk of the archipelago to Yemen in 1998.
2000 October - US naval vessel USS Cole damaged in al-Qaeda suicide attack in Aden. Seventeen US personnel killed.
2001 February - Violence in run-up to disputed municipal polls and referendum, which backs extension to presidential term and powers.
2002 February - Yemen expels more than 100 foreign Islamic clerics in crackdown on al-Qaeda.
2002 October - Al-Qaeda attacks and badly damages oil supertanker MV Limburg in Gulf of Aden, killing one and injuring 12 crew members, and costing Yemen dear in lost port revenues.
2004 June-August - Hundreds die as troops battle Shia insurgency led by Hussein al-Houthi in the north.
2005 March-April - More than 200 people are killed in a resurgence of fighting between government forces and supporters of the slain rebel cleric Hussein al-Houthi.
2007 January-March - Scores are killed or wounded in clashes between security forces and al-Houthi rebels in the north. Rebel leader Abdul-Malik al-Houthi accepts a ceasefire in the summer.
2008 January - Renewed clashes with Houthi rebels.
2008 September - A-Qaeda attack on US embassy in Sanaa kills 12 people.
Demands for reform
2008 November - Police fire warning shots at opposition rally in Sanaa. Demonstrators demand electoral reform and fresh polls.
2009 August - The Yemeni army launches a fresh offensive against Houthi rebels in the northern Saada province. Tens of thousands of people are displaced by the fighting.
2009 December - Yemen-based branch of al-Qaeda claims it was behind failed attack on US airliner.
2010 September - Thousands flee government offensive against separatists in southern Shabwa province.
2010 October - Global terror alert after packages containing explosives originating in Yemen are intercepted on cargo planes bound for the US.
2011 September - US-born al-Qaeda leader in Yemen, Anwar al-Awlaki, is killed by US forces.
Unity government, growing violence
2011 November - President Saleh agrees to hand over power to his deputy, Abdrabbuh Mansour Hadi, after months of protests. A unity government including prime minister from opposition formed.
2012 February - Abdrabbuh Mansour Hadi inaugurated as president after uncontested elections, but is unable to counter al-Qaeda attacks in the capital as the year goes on.
2014 February - Presidential panel gives approval for Yemen to become a federation of six regions, as part of a deal to accommodate Houthi and southern grievances.
2014 August - President Hadi sacks his cabinet and overturns a controversial fuel price rise following two weeks of anti-government protests in which Houthi rebels are heavily involved.
2014 September - Houthi rebels seize control of the most of Sanaa and reject draft constitution proposed by government.
2015 February - Houthis appoint presidential council to replace President Hadi, who flees to his southern stronghold of Aden.
2015 March - Islamic State carries out its first major attacks in Yemen - two suicide bombings targeting Shia mosques in Sanaa, in which 137 people are killed.
Civil war breaks out in earnest as Saudi-led coalition of mainly Gulf Arab states launches air strikes against Houthi targets and imposes naval blockade, in order to halt their advance on Aden.
2015 June - Latest leader of al-Qaeda in Arabian Peninsula, Nasser al-Wuhayshi, is killed in a US drone strike in Yemen.
2016 May-June - Islamic State group claims responsibility for a number of attacks, including a suicide car bombing that killed at least 40 army recruits in Aden.
2017 June-November - Outbreak of cholera kills 2,100 and affects almost 900,000 others, medical agencies say.
2017 December - Former president Ali Abdullah Saleh is killed after fierce fighting in the capital Sanaa.
2018 January - Southern Yemeni separatists - backed by the United Arab Emirates - seize control of Aden.
2018 November - US calls for cease-fire, after months of fighting around the key Houthi-held port of Hudaydah and a mounting humanitarian crisis.