Syrian civil war: Areas controlled by the Syrian opposition in Ghouta, Damascus, were attacked by rockets (launcher pictured) containing sarin, killing at least 281 people.

The Syrian civil war began with the Syrian revolution in March 2011, when popular discontent with the Ba'athist regime ruled by Bashar al-Assad triggered large-scale protests and pro-democracy rallies across Syria, as part of the wider Arab Spring. The Assad regime responded to the protests with lethal force, sparking a civil war. The Syrian revolution lasted almost 14 years and culminated in the fall of the Assad regime in December 2024. Many sources regard this as the end of the civil war.

The Syrian opposition was an umbrella term for the Syrian revolutionary organizations that opposed Bashar al-Assad's Ba'athist regime during the Syrian Revolution and Syrian civil war. The opposition factions in Syria became active as grassroots movements during the mass demonstrations against the Ba'athist regime. The Free Syrian Army (FSA) was the most prominent armed revolutionary group in the initial stages of the war; but it declined and became decentralized by 2015. By 2021, Hay'at Tahrir al-Sham (HTS) had become the strongest armed faction within the Syrian opposition.

Ghouta is a countryside area in southwestern Syria that surrounds the city of Damascus along its eastern and southern rim.

The Ghouta chemical attack was a chemical attack carried out by the forces of Syrian President Bashar al-Assad, in the early hours of 21 August 2013 in Ghouta, Syria during the Syrian civil war. Two opposition-controlled areas in the suburbs around Damascus were struck by rockets containing the chemical agent sarin. Estimates of the death toll range from at least 281 people to 1,729. The attack was the deadliest use of chemical weapons since the Iran–Iraq War.