Syrian government forces pounded opposition-held rebel areas of Damascus on Monday after pushing back an assault that saw rebels try to fight their way into the capital.
Here are key dates in the fight for Damascus and its suburbs, which erupted a year after Syria's conflict broke out in 2011.
- Battle for Damascus starts -
- July 17, 2012: the rebel Free Syrian Army (FSA) announces "the battle for the liberation of Damascus".
Fierce fighting break out in the outskirts of the capital between Syrian army soldiers and rebels.
The army fires mortar shells on several Damascus districts where rebels are entrenched, before bringing helicopters into action.
- July 18, 2012: four senior officials, including Assad's brother-in-law Assef Shawkat, are killed in a suicide bombing at National Security headquarters.
July 23, 2012: the regime deploys elite army units in Damascus and the army retakes control of the biggest part of the capital.
From August 20-26 the army carries out a major offensive on the town of Daraya, a Damascus suburb, killing more than 500 people.
- Sarin gas attack -
August 21, 2013: hundreds of people are killed in what the opposition says are chemical weapons attacks on rebel bastions near Damascus, including one in Moadamiyet al-Sham. The regime denies the charge.
In late August a US intelligence report blames Syria's government for the attack with "high confidence" and says that 1,429 people were killed, including 426 children.
September 14, 2013: the United States and Russia agree on a plan to eliminate Syria's chemical weapons by the middle of 2014, averting the prospect of punitive US strikes.
Two days later, a UN report says there is clear evidence that sarin gas was used in the August 21 attack.
- Neighbourhoods under siege -
In 2012, regime troops and their allies cut off access to the rebel towns of Zabadani and Madaya, near the border with Lebanon.
The siege of Madaya, which became total in mid-2015, leads to up to 60 deaths due to malnutrition and famine, including children, aid groups say.
Other rebel-controlled districts are also besieged in Eastern Ghouta, a rural area near Damascus.
In August 2016, the last rebels evacuate their former stronghold of Daraya, west of Damascus, under an accord struck by the regime and rebels following a government siege of four years.
- Wadi Barada captured -
In late January 2017, the army recaptures Wadi Barada, a flashpoint area that supplies water to Damascus.
Residents had been without water for over a month, with the government blaming rebel groups for cutting off access.
In March, a UN investigation says regime bombing of the main spring in Wadi Barada had left more than five million people without water access, calling it a "war crime."
On March 19, rebels from former Al-Qaeda affiliate Fateh al-Sham Front attack regime positions in eastern Damascus in a bid to fight their way into the city centre.
They are rolled back by Syrian government forces and intense air strikes on rebel-held neighbourhoods of Damascus follow.