Damascus: Syria`s civil war, which has killed more than 270,000 people and forced millions to flee their homes, erupted in 2011 when government forces turned their weapons on protesters demanding political change.
The following are 10 key dates in the brutal conflict:-
March 15: Unprecedented protests inspired by the Arab Spring erupt, demanding reform after 40 years of iron-fisted rule by President Bashar al-Assad`s family.
- Security forces crack down on protesters in Damascus and Daraa, known as "the cradle of the uprising", where 100 people are reportedly killed on March 23.
- The regime claims it is cracking down on "an armed rebellion" by radical Islamists, while Britain, France and the United States denounce the repression.
- Protests spread, with demonstrators calling for Assad`s ouster.
- July 17: Moderate rebels from the Free Syrian Army declare that the battle for Damascus has begun, but the government holds its ground.
- July 19: Rebels launch an offensive in the northern city of Aleppo, which has since been divided between rebel-held neighbourhoods in the east and regime-held districts in the west.
- April 30: Hassan Nasrallah, chief of the powerful Lebanese Shiite group Hezbollah, acknowledges that his troops are fighting in Syria in support of Assad.
- August 21: Hundreds of people are killed in chemical weapons attacks targeting rebel bastions near Damascus. The West accuses Assad`s regime.
- In September, the United States and Russia agree on a plan to eliminate Syria`s chemical weapons, narrowly heading off US strikes.
- January 14: The jihadist Islamic State group, which emerged in Syria in 2013, seizes Raqa, the first provincial capital to fall out of regime control.
- June 29: IS declares the establishment of an Islamic "caliphate". It later claims numerous murders, including of Western hostages.
- May 9: Syrian troops recapture the Old City of Homs, after a two-year siege and near-daily bombardment. Rebels withdraw.
- January 26: Kurdish forces backed by US-led air strikes drive IS out of the flashpoint town of Kobane on the Turkish border, after months of fierce fighting.
- March 28: Syria`s Al-Qaeda affiliate, Al-Nusra Front, backed by rebel allies, seizes most of the northwestern city of Idlib, the second provincial capital after Raqa to fall out of government hands.
- In May Assad says that such setbacks do not mean the conflict is lost, but in July he acknowledges the shrinking ranks of his army.
- September 30: Russia launches air strikes on Syria, saying it is targeting "terrorists" including IS, but it faces accusations of hitting non-jihadist rebels and civilians as it seeks to bolster Assad.
- February 27: An unprecedented "cessation of hostilities" comes into force. It applies to combat zones between Russian-backed regime forces and non-jihadist rebels, but does not apply to the more than half of the country`s territory that is controlled by extremist groups.