From the bloody repression of peaceful protests against President Bashar al-Assad's regime to foreign intervention, below are key dates in Syria's civil war as it enters its eighth year. The complex conflict has left more than 350,000 people dead, according to the Syrian Britain-based Observatory for Human Rights, while millions have been displaced and the country lies in ruins.

REVOLT AND REPRESSION

On March 15, 2011, unprecedented protests demand civil liberties and the release of political prisoners after 40 years of repressive rule by the Assad family. Denouncing "an armed rebellion by Salafist groups", the regime represses demonstrations in Damascus and the southern city of Daraa but protests continue.

In July, defecting army colonel Riad al-Assad sets up the Turkey-based rebel Free Syrian Army (FSA). Islamist groups join the revolt.

AIR STRIKES, HEZBOLLAH, IRAN

In March 2012, regime forces take control of the rebel stronghold in third city Homs after a month of bombardment. Other bloody operations are carried out, notably in the central city of Hama, after massive anti-regime protests.

In July, FSA fighters launch a battle for Damascus but the government holds firm. From 2013, regime helicopters and planes unleash crude barrel bombs on rebel zones.

The same year, Iran-backed Lebanese Shia militant group Hezbollah says it is fighting alongside Syrian government forces.

CHEMICAL WEAPONS

In August 2013, Washington accuses the regime of killing more than 1,400 people with chemical weapons in rebel-held districts near Damascus. In September, the United States and Assad ally Russia agree a plan to eliminate Syria's chemical weapons, averting punitive US strikes against the regime.

RISE OF THE JIHADISTS

In January 2014, hostilities between jihadists of the Islamic State of Iraq and the Levant (ISIL) and rebel groups turn into an open war in the north.

ISIL, the future Islamic State (IS) group, takes Raqa -- the first provincial capital to fall out of regime control -- from rebel forces. The jihadist offensive allows Damascus to justify its fight as a battle against "terrorism".

TURKISH OFFENSIVE

In an added complication to the drawn-out conflict, Turkey launches an operation in January 2018 against the powerful Kurdish People's Protection Units (YPG) which played a key role in beating back IS. The militia controls the Afrin region on the border with Turkey, and Ankara is wary of Kurdish aspirations for autonomy, labelling the YPG a "terror group".

BLITZ OF EASTERN GHOUTA

On February 18, the Syrian regime launches a ferocious assault on the remaining rebel-held enclave near Damascus, Eastern Ghouta. In just over three weeks, the Russian-backed onslaught kills more than 1,100 civilians, according to the Observatory.