Qatar profile - Timeline

A chronology of key events:

1825 - Al-Thani dynasty establishes control over Qatar, which tries to establish independence from Bahraini suzerainty.

1871 - The Al-Thanis submit to Ottoman overlordship.

1916 - Deal signed under which Britain controls Qatar's external affairs in return for guaranteeing its protection.

1939 - Oil reserves discovered. Exploitation is delayed by World War II, but oil comes to replace pearling and fishing as Qatar's main source of revenue.

1950s - Oil revenues fund the expansion and modernisation of Qatar's infrastructure.

1971 - Qatar becomes independent on 3 September.

1972 - Khalifa bin Hamad Al Thani takes power in a palace coup after infighting in the ruling family.

1990 August - After Iraq invades Kuwait, Qatar says it will allow foreign forces on its soil. Qatari troops later take part in the liberation of Kuwait.

1995 - Sheikh Khalifa deposed by his son, Hamad, in a bloodless coup.

1996 - Al-Jazeera satellite TV launches, as an independent channel funded by the emir. Based in Qatar but broadcasting to much of the Arab world, it establishes a reputation for its news coverage and willingness to tackle controversial issues.

1999 - Municipal elections, the first democratic polls since 1971, mark the start of a democratisation programme.

2002 - Qatar looms large in US plans for a possible war against Iraq. Its al-Udeid air base is developed and expanded. Washington says it will deploy US Central Command staff to Qatar.

2003 March-April - Qatar-based US Central Command forward base serves as the nerve centre in the US-led military campaign in Iraq.

2005 June - Qatar's first written constitution comes into effect, providing for some democratic reforms.

2005 November - Qatar and the US launch a $14 billion joint project to build the world's largest liquefied natural gas plant. Most of the gas will be exported to the US.

2008 December - Saudi Arabia and Qatar agree final delineation of borders and pledge to boost co-operation after diplomatic relations restored in March.

2009 January - Qatar cuts trade ties with Israel over Gaza offensive. Was sole Gulf state to have trade ties with Israel.

2010 December - Qatar wins bid to host 2022 Fifa World Cup.

2011 March - Qatar joins international military operations in Libya, and goes on to arm Islamist opposition groups.

2011 November - Emir Hamad bin Khalifa al-Thani says elections to the advisory council will be held in 2013, in what would be Qatar's first legislative elections, but these are repeatedly postponed.

2012 January - The Afghan Taliban say they are setting up a political office in Qatar to facilitate talks.

2012 October - Sheikh Hamad bin Khalifa al Thani visits Gaza, the first head of state to do so since Hamas took power there five years previously.

2013 June - Sheikh Tamim bin Hamad al-Thani takes over as emir after his father abdicates.

2014 September - Qatar and four other Arab states take part in US-led air strikes on Islamic State militants in Syria.

2015 March - Qatar and four other GCC states take part in Saudi-led air strikes on Houthi rebels in Yemen.

2016 December - Government says it is abolishing the controversial labour sponsorship system or "kafala" that forces foreign workers to seek their employers' consent to change jobs or leave the country.

2017 June - Diplomatic crisis as Saudi Arabia leads an air, land and sea blockade by Arab countries, in an attempt to get Qatar to cut its alleged connections with terrorism and distance itself from Iran.

2018 December - Qatar announces that it will withdraw from the Organisation of Petroleum Exporting Countries (OPEC) in January, citing its greater reliance of gas exports, although many regional analysts see it as a symbolic move away from Saudi influence.