A chronology of key events:
1527 - Portuguese cartographer Diego Ribero depicts the Comoros islands on a European map for the first time.
1886 - Comoros become a French protectorate.
1912 - Comoros formally become a French colony administered from Madagascar.
1942 - British forces invade the Comoros and Madagascar, toppling the pro-Vichy administration and handing the territories over to the Free French government of Charles de Gaulle.
1947 - Comoros become an overseas territory of France and are given representation in the French parliament.
1961 - Comoros given autonomy.
1974 - Three of the islands making up the Comoros vote for independence, but a fourth island, Mayotte, votes to stay with France.
1975 July - Comoros unilaterally declares independence, with Ahmed Abdallah as president.
1975 August - Abdallah deposed in coup assisted by French mercenary Colonel Bob Denard, and replaced by Prince Said Mohammed Jaffar.
1976 - Jaffar replaced by Ali Soilih, who tries to turn the country into a secular, socialist republic.
1978 - Soilih toppled and killed by mercenaries led by Denard, who restore Abdallah to power.
1989 - Abdallah assassinated by presidential guard under command of Denard, who stages coup. France intervenes, Denard leaves islands.
1990 - Said Mohamed Djohar elected president.
1995 - Djohar removed in a coup attempt led by Denard. French troops intervene, Denard surrenders.
1996 - Mohamed Abdulkarim Taki elected president, drafts a constitution which extends the authority of the president and establishes Islam as the basis of law.
1997 August - The islands of Anjouan and Moheli declare independence from the Comoros.
1997 September - Troops from the island of Grande Comore land in Anjouan to try to prevent its secession, but are routed.
1998 - President Taki dies, apparently of heart attack, and is replaced by an acting president, Tadjidine Ben Said Massounde, pending elections.
1999 April - Massounde signs an autonomy agreement in Madagascar, but the delegates from Anjouan and Moheli refuse to follow suit, saying they must first consult their people, thereby prompting violent demonstrations in Grande Comore against people of Anjouan origins.
1999 April - Massounde ousted in a coup led by the chief of the General Staff, Col Azali Assoumani.
2001 March - Azali Assoumani says the country will return to civilian rule in 2002 after new institutions of government had been set up. He also said he would not stand for election.
2001 August - A "military committee" seizes power in the breakaway island of Anjouan with aim of rejoining the Comoros.
2001 September - In Anjouan, a day-old takeover by Major Combo Ayouba is crushed by Major Mohamad Bacar, who leads the military government set up in August.
2001 November - Anjouan sees another failed coup attempt, this time by Colonel Said Abeid, who is against Bacar's reunification efforts.
Autonomy for islands
2001 December - Voters back a new constitution that will keep the three islands as one country, but will grant each one greater autonomy.
2002 April - Colonel Mohamed Bacar elected leader of Anjouan and Mohamed Said Fazul elected leader of Moheli. Azali Assoumani named president of reunited Comoros.
2002 May - Mze Abdou Soule Elbak is elected island president of Grande Comore, also the base of Azali Assoumani, the overall ruler of the reunited Comoros.
2003 February - Security forces say they have foiled a coup plot against President Assoumani.
2003 December - Leaders of semi-autonomous islands reach a power-sharing deal, paving the way for elections
2004 March-April- Local elections for assemblies on the three semi-autonomous islands. Supporters of federal president, Azali Assoumani, win only 12 of 55 seats. Elections are held in April for 33-member national assembly - Assemblee de l'Union.
2004 June-July- National assembly opens. President Assoumani Azali names members of first federal government.
2005 January - First visit to France by a Comoran leader for 30 years.
2005 April and November - Mount Karthala, one of the world's largest active volcanos, spews ash over Grande Comore. Thousands of villagers flee.
2006 May - Muslim cleric Ahmed Abdallah Mohamed Sambi, from Anjouan, wins federal presidential elections.
2007 May - The African Union sends troops to help keep the peace in June's elections after Anjouan president Mohamed Bacar refuses to stand down.
2007 June - Anjouan holds local elections in defiance of the federal government and the African Union. Mohamed Bacar is inaugurated as Anjouan's president.
2007 October - The African Union imposes travel sanctions on Anjouan leader Mohamed Bacar and other government officials and freezes their foreign assets while calling for fresh elections.
2007 November - AU begins naval blockade of Anjouan island.
2008 March - Comoran and AU troops land on Anjouan and recapture it. France takes renegade leader Mohamed Bacar into custody.
2009 March - The island of Mayotte votes to fully integrate with France. The Comoros government, which lays claim to the island, terms the referendum null and void.
2009 May - Voters in a referendum approve extension of president's term of office. The extension is opposed by the opposition and many residents of Moheli.
2009 June - Yemenia Airways plane crashes off Comoros, killing all but one of 153 people on board. Comoran expatriates demonstrate in France after suggestions plane may have been faulty.
2009 December - President Sambi's party wins landslide victory in parliamentary election.
2010 April - Libyan soldiers take up duty in the presidential guard as ''trainers''.
2010 June - Political leaders, after some delay, agree on elections timetable starting in November with primaries for the presidency.
2010 December - Ikililou Dhoinine wins presidential elections, and takes office in May 2011.
2013 April - Several people are detained, accused of plotting against the government.
2013 November - Comoros comes out on top in a survey of women's rights in 21 Arab League states. The poll by the Thomson Reuters Foundation surveyed 336 gender experts.
2015 February - Parliamentary elections.