Key events since the start of the Libya conflict, as rebel forces close in on the capital Tripoli:

February 15-19: Inspired by revolts in other Arab countries, including neighbouring Tunisia and Egypt, a rebellion breaks out including in Benghazi, Libya's second city.

March 19: With troops loyal to Libyan leader Moamer Gaddafi threatening rebel-held Benghazi, French, US and British forces launch UN-mandated air attacks and push them back.

March 30: Libyan foreign minister Mussa Kussa defects. Dozens of political and military figures follow suit.

March 31: The North Atlantic Treaty Organisation takes over formal command of the military operation.

April 20: France and Italy join Britain in sending military advisers to assist the rebels.

May 1: Gaddafi escapes a NATO air strike, which the regime says kills his youngest son, Seif al-Arab, and three grandchildren.

June 1: NATO says the operation, originally due to wind up at the end of June, will continue until the end of September.

June 9: An International Contact Group on Libya meets in Abu Dhabi, and finalises a fund aimed at helping the rebels.

June 20-21: Gaddafi's regime says 24 civilians have been killed in NATO air strikes.

June 27: The International Criminal Court (ICC) issues an arrest warrant for Gaddafi for war crimes and crimes against humanity.

June 29: France says it has air-dropped weapons to rebel forces.

July 14: The rebels consolidate their positions in the west, and begin an offensive on the oil town of Brega. NATO dismisses accusations that its attacks have killed more than 1,100 civilians.

July 15: In Istanbul, the Contact Group designates the rebels as Libya's legitimate rulers, paving the way for the release of frozen Gaddafi regime assets.

July 25: NATO says it supported rebels by hitting a military facility, armoured vehicles, tanks and light military vehicles around Brega.

July 28: Rebel military chief General Abdel Fatah Yunis is assassinated as insurgent fighters pound forces loyal to Gaddafi in the west.

August 5: The regime denies the death of Gaddafi's son Khamis in a NATO raid, as announced by rebels.

August 6: The western town of Bir al-Ghanam falls to the rebels.

August 8: Rebel leader Mustafa Abdel Jalil sacks the entire executive office of his government.

August 9: Libyan authorities accuse NATO of a "massacre" of 85 villagers in air strikes south of Zliten in western Libya. NATO insists it has no evidence of the civilian deaths.

August 10: EU widens sanctions against the regime.

August 15: Rebels say they have seized ‘most’ of Zawiyah, the final hurdle on the road to Tripoli as Gaddafi calls the insurgents ‘rats’ and predicts their demise.

The UN chief's special envoy visits Tunis for talks on Libya's future.

Gaddafi's deputy interior minister flies out to Cairo.

August 20: Fighting erupts in Tripoli as rebels close in on the capital after claiming the oil city of Brega, a day after seizing Zawiyah and Zliten.

August 21: Libyan rebels enter Tripoli from the west, greeted by cheering crowds, witnesses say, and launch an offensive. Gaddafi vows he will not surrender and boasts he will ‘emerge victorious’ in the battle for the capital. NATO says the regime is ‘crumbling’