In what year did the Syrian Civil War begin?

2011

The Syrian Civil War (Arabic: الحرب الأهلية السورية‎‎, Al-ḥarb al-ʼahliyyah as-sūriyyah) grew out of the unrest of the 2011 Arab Spring and escalated to armed conflict after President Bashar al-Assad's government violently repressed a revolt.

The Syrian government has since then refused efforts to negotiate with what it describes as armed terrorist groups.

The war is being fought by several factions: the Syrian Government and its various supporters, a loose alliance of Sunni Arab rebel groups (including the Free Syrian Army), the majority-Kurdish Syrian Democratic Forces, Salafi jihadist groups (including al-Nusra Front) who often co-operate with the Sunni rebels, and the Islamic State of Iraq and the Levant (ISIL).

The factions receive substantial support from foreign actors, leading many to label the conflict a proxy war waged by both regional and global powers.

https://en.wikipedia.org/wiki/Syrian_Civil_War