More than 250,000 Syrians have lost their lives in four-and-a-half years of armed conflict, which began with anti-government protests before escalating into a full-scale civil war. More than 11 million others have been forced from their homes as forces loyal to President Bashar al-Assad and those opposed to his rule battle each other – as well as jihadist militants from so-called Islamic State. This is the story of the civil war so far, in eight short chapters.
1. Uprising turns violent
Pro-democracy protests erupted in March 2011 in the southern city of Deraa after the arrest and torture of some teenagers who painted revolutionary slogans on a school wall. After security forces opened fire on demonstrators, killing several, more took to the streets.
The unrest triggered nationwide protests demanding President Assad’s resignation. The government’s use of force to crush the dissent merely hardened the protesters’ resolve. By July 2011, hundreds of thousands were taking to the streets across the country.
Opposition supporters eventually began to take up arms, first to defend themselves and later to expel security forces from their local areas.
2. Descent into civil war
Violence escalated and the country descended into civil war as rebel brigades were formed to battle government forces for control of cities, towns and the countryside. Fighting reached the capital Damascus and second city of Aleppo in 2012.
The conflict is now more than just a battle between those for or against Mr Assad. It has acquired sectarian overtones, pitching the country’s Sunni majority against the president’s Shia Alawite sect, and drawn in regional and world powers. The rise of the jihadist group Islamic State (IS) has added a further dimension.
3. War crimes
A UN commission of inquiry has evidence that all parties to the conflict have committed war crimes – including murder, torture, rape and enforced disappearances. They have also been accused of using civilian suffering – such as blocking access to food, water and health services through sieges – as a method of war.
The UN Security Council has demanded all parties end the indiscriminate use of weapons in populated areas, but civilians continue to die in their thousands. Many have been killed by barrel bombs dropped by government aircraft on gatherings in rebel-held areas – attacks which the UN says may constitute massacres.
IS has also been accused by the UN of waging a campaign of terror. It has inflicted severe punishments on those who transgress or refuse to accept its rules, including hundreds of public executions and amputations. Its fighters have also carried out mass killings of rival armed groups, members of the security forces and religious minorities, and beheaded hostages, including several Westerners.
4. Chemical weapons
Hundreds of people were killed in August 2013 after rockets filled with the nerve agent sarin were fired at several suburbs of Damascus. Western powers said it could only have been carried out by Syria’s government, but the government blamed rebel forces.
Facing the prospect of US military intervention, President Assad agreed to the complete removal and destruction of Syria’s chemical weapons arsenal.
The operation was completed the following year, but the Organisation for the Prohibition of Chemical Weapons (OPCW) has continued to document the use of toxic chemicals in the conflict. Investigators found chlorine was used “systematically and repeatedly” in deadly attacks on rebel-held areas between April and July 2014.
IS has also been accused of using homemade chemical weapons, including sulphur mustard. The OPCW said the blister agent was used in an attack on the northern town of Marea in August 2015 that killed a baby.