The Lebanese Shia group Hezbollah led a political campaign against the government of Fouad Siniora.
The crisis had paralysed much of the government and left Lebanon without a president for five months.
Hezbollah, allegedly backed by Iran and Syria, was the only Lebanese faction allowed to keep its weapons after the civil war ended in 1990, to fight Israeli forces occupying the south.
Israel withdrew in 2000 and the fate of Hezbollah's weapons is at the heart of the current political crisis.
Here is a chronology of events:
November 11 - Five pro-Syrian Shia Muslim ministers from Hezbollah and its ally, Amal, resign after the collapse of talks on giving their camp more say in government.
November 21 - Pierre Gemayel, the industry minister, is assassinated.
December 1 - Hezbollah, Amal and supporters of Michel Aoun, a Christian leader, camp outside the office of Fouad Siniora, the prime minister, in Beirut in open-ended
campaign to topple the government.
January 25 - Aid conference in Paris pledges more than $7.6bn to help Lebanon recover from its 2006 war with Israel.
June 13 - Anti-Syrian parliamentarian Walid Eido and five other people killed by a car bomb near a Beirut beach club.
September 2 - Lebanese troops seize complete control of Nahr al-Bared camp after months of fighting with Fatah al-Islam fighters which kills more than 420 people, including 168 soldiers.
September 19 - Car bomb in Beirut kills anti-Syrian Christian legislator Antoine Ghanem and six other people.
November 23 - Emile Lahoud leaves presidential palace at end of his term without a successor being elected. Next day Siniora says his cabinet is assuming executive powers.
December 5 - Speaker Berri says rival Lebanese leaders have agreed on General Michel Suleiman as president, although parliament has yet to elect him.
December 12 - Car bomb kills Brigadier-General Francois al-Hajj, the army's head of operations, in a Christian town east of Beirut.
January 15 - Car bomb in Christian area of Beirut kills at least three people and wounds 16, damages a US embassy car and destroys others.
January 25 - Wisam Eid, a captain in a Lebanese police intelligence unit, is killed by a bomb blast in mainly Christian east Beirut. At least five other people are killed.
February 11 - Three army officers and 16 soldiers are charged over the killing of seven opposition protesters on January 27.
February 14 - Hezbollah holds mass Beirut funeral for its assassinated commander Imad Moughniyah, who was killed in a bomb blast in Syria the day before.
April 20 - In the Christian town of Zahle, two local officials of the Christian Phalange party, a member of the ruling anti-Syrian coalition, are killed.
April 22 - Parliament fails to hold a session to elect a president, the 18th time it has been unable to hold a vote.
May 6 - Tension between the government and Hezbollah escalates when the cabinet says the group's communication network was an attack on the country's sovereignty.
Hezbollah says it is infuriated by government allegations it was spying on Beirut airport and by the cabinet's decision to fire the head of airport security who is close to the opposition.
May 7 - About 10 people are wounded as government supporters clash with fighters loyal to the Hezbollah-led opposition in Beirut after followers of Hezbollah paralysed the capital.
May 8 - Hassan Nasrallah, Hezbollah's leader, says the government has declared war against the group after its decision to dismantle and take legal action over the group's communication network.
Gun battles break out in Beirut, leaving several dead and many wounded.
An offer by Saad al-Hariri, the governing coalition leader, to refer the issue to the army, which has stayed neutral, is rejected by Hezbollah.
May 9 - Opposition forces seize control of west Beirut.
May 10 - Fouad Siniora, Lebanon's prime minister, declares that the government will never declare war on Hezbollah but says the Shia group is trying to stage a coup.
The army rescinds the government's demands, saying it will reinstate Beirut airport's head of security, who the government alleged was close to Hezbollah, and will handle the issue of the Hezbollah's communication network.
Army also calls on the opposition to withdraw its fighters from the streets.
Hezbollah and other groups allied to the opposition begin to pull their forces from Beirut, with the army taking over in a neutral security role.
May 10-11 - Pro- and anti-government fighters clash overnight in the northern city of Tripoli. The Lebanese army is deployed to restore calm.
May 16 - Lebanese leaders from the government and the opposition meet in Doha, capital of Qatar, for crisis talks sponsored by the Arab League.
May 21 - Government and opposition representatives reach a power-sharing agreement after five days of talks in Qatar.
The Hezbollah-led opposition wins a greater share of seats in the cabinet, giving it an effective veto over any decisions reached by the executive.
Electoral districts in the capital Beirut are also re-organised in an effort to make them more representative, and both sides agree to meet urgently.
May 25 - Suleiman is elected the new president in line with the Doha pact.
May 28 - Suleiman reappoints Siniora as prime minister at the head of a new unity government.
June 18 - Three people are killed and four others wounded in clashes between pro- and anti-government supporters in the Bekaa valley.
June 22 - One person is killed and at least 24 injured after heavy fighting erupts between pro- and anti-government factions in the northern city of Tripoli. The clashes force the withdrawal of the Lebanese army from the area.
July 11 - National unity government announced.