1956: Pakistan is proclaimed an Islamic republic, Iskander Mirza becomes first president
1958: Martial law is declared, Mirza is sent into exile and Field Marshal Ayub Khan declares himself president.
1962: Martial law suspended.
1965: Ayub Khan wins presidential election.
1969: General Yahya Khan takes over following Ayub Khan's resignation, martial law declared.
1971: President Yahya cedes power to Zulfiqar Ali Bhutto who becomes president.
1973: Martial law suspended as Bhutto becomes prime minister and Fazal Ilahi Chaudhry becomes president under new constitution.
1977: General election is followed by rioting as Bhutto's Pakistan People's party is accused of vote rigging. General Zia ul-Haq becomes president and martial law declared.
Zia died in a mysterious plane crash [AP]
1978: Zia becomes Pakistan's sixth president.
1979: Political parties banned, Bhutto is hanged.
1985: Martial law and ban on political parties lifted.
1986: Bhutto's daughter, Benazir, returns from exile.
1988: Zia dies in mysterious plane crash. Ghulam Ishaq Khan becomes president, Benazir Bhutto becomes first female prime minister of a Muslim country.
1990: Bhutto dismissed on charges of corruption. Nawaz Sharif elected prime minister.
1993: Khan and Sharif resign under pressure from the army. Election returns Bhutto as prime minister. Wasim Sajjad becomes interim president. Sardar Farooq Leghari replaces Sajjad as president.
1996: Leghari dismisses Bhutto amid allegations of corruption.
1997: Nawaz Sharif wins election to return as prime minister. Wasim Sajjad becomes interim president.
1998: Muhammad Rafiq Tarar becomes 11th president of Pakistan.
1999: Bhutto and her husband convicted of corruption. Bhutto stays out of the country. Sharif overthrown in coup led by General Pervez Musharraf.
Musharraf took power in a military coup [AFP]
2000: Sharif convicted of hijacking and terrorism and sentenced to life imprisonment. He is pardoned by military authorities and goes into exile in Saudi Arabia.
2001: Musharraf declares himself president while still head of the army.
2002: Musharraf elected as president in referendum criticised as unconstitutional. First general election since start of military rule. Mir Zafarullah Jamali elected prime minister.
2004: Musharraf announces he will continue as head of the army despite having previously said he would give up the role.
April 2007: In April Musharraf suspends Iftikhar Mohammed Chaudhry, the chief justice, following demonstrations. Chaudhry is reinstated in July.
August 2007: Pakistan's supreme court rules Sharif can return from exile, but he is sent to Saudi Arabia within hours of his return in September.
The same month Musharraf agrees to step down as head of the army after presidential elections in October.
October 2007: Musharraf wins presidential elections in Pakistan, but must await decision from the supreme court as to whether he was eligible to be a candidate.
Also in October, Benazir Bhutto, former Pakistani prime minister, returns from exile to Pakistan. During a parade in the city of Karachi attended by thousands of her supporters, a suicide bomb attack kills more than 130 of her supporters.
November 4, 2007: Musharraf declares a state of emergency in Pakistan. Troops surround Islamabad's state-run television and radio stations and police surround the supreme court.
November 28, 2007: Musharraf steps down as army chief, meeting a key demand of the international community, and ending eight years of divisive military rule. Control of the army and its nuclear arsenal are handed to General Ashfaq Kiyani, a former intelligence chief. Musharraf is sworn in as a civilian president the next day.
December 15, 2007: Musharraf lifts a nationwide state of emergency amid mounting criticism that general elections scheduled for January will not be free and fair. Musharraf cancelled the six-week long emergency law a day after he made changes to Pakistan's constitution.
December 21, 2007: At least 50 people are killed in a suicide bombing at a mosque in northwest Pakistan, apparently targeting Aftab Khan Sherpao, the country's former interior minister.
December 27, 2007: Benazir Bhutto, former Pakistani prime minister, is killed by a suicide bomber who first fired shots at her before blowing himself up during an election rally in Rawalpindi, 14km south of Islamabad.
January, 2008: Authorities arrest two suspects including a 15-year-old-boy who admitted to being a back-up suicide bomber if the Rawalpindi attack on Bhutto had failed.
February 16, 2008: Campaigning ends grimly when a suicide car bomber ploughs into a meeting of Bhutto's supporters in the northwestern tribal town of Parachinar, killing 47 people and wounding more than 100.
Well over 450 people have been killed so far this year in the run up to the election, and fear could lead to a low turnout.
February 18, 2008: Pakistanis head to the polling stations with 80,000 troops backing up police. Nearly 81 million people are registered to vote.
Parties led by Bhutto's widower Asif Ali Zardari (Pakistan People's Party) and Sharif (Pakistan Muslim League (Nawaz) win a resounding victory over the pro-Musharraf Pakistan Muslim League.
March 24, 2008: Parliament elects Bhutto aide Yousuf Raza Gilani as prime minister.
August 7, 2008: The ruling coalition says it would launch an impeachment process against Musharraf.
August 17, 2008: Coalition says it has finalised impeachment charges.
August 18, 2008: Musharraf announces his resignation as Pakistan's president.
August 21, 2008: At least 64 people killed in a double suicide attack near Islamabad.
August 23, 2008: Zardari decides to stand for the presidency.
August 25, 2008: The government outlaws fighter group Tehreek-e-Taliban Pakistan (TTP).
August 25, 2008: Sharif's party quits Pakistan's ruling coalition over differences on the reinstatement of the judges sacked by Musharraf.
August 29, 2008: Zardari moves house amid fears of attacks being made on his life.
September 3, 2008: Snipers fire at Prime Minister Gilani's motorcade in a failed assassination attempt.