For nearly 14 years, Syria's Bashar al-Assad resisted the Arab Spring that ousted leaders across the region.
Assad had for years relied on his alliances with Russia, Iran and in order to maintain power.
While leading a merciless war of survival for his rule, he presented himself to his people and the outside world as Syria's only viable leader in the face of a threat from Islamist forces.
But an Islamist-led rebel offensive that started on 27 November wrested city after city from Assad's control, and eventually they captured the capital Damascus. Assad fled to Russia, where he and his family were granted asylum.
Here's how Assad came to power and the events that led to his downfall.
From an opthalmologist to Syria's ruler
Bashar al-Assad was never meant to become Syria's president, but his life changed radically when his older brother Bassel, who was being groomed to inherit power from their father Hafez al-Assad, died in a car accident in 1994.
Bashar quit his studies in ophthalmology and left London, where he had met his wife Asma, a British-Syrian and Sunni Muslim who worked for financial services firm JP Morgan.
Back home, he took a course in military studies and was tutored in politics by his father, who had been Syria's president since 1971.
When Hafez al-Assad died in 2000, Bashar became president by referendum, running unopposed, then winning a second term in 2007.
Sworn in at the age of 34, Assad was initially seen by Syrians pining for freedoms as a reformer who could do away with years of repression and introduce economic liberalisation.
In the early days, Assad would be seen driving his own car or having dinner at restaurants with his wife.
He relaxed some of the heavy restrictions that existed under his father.
Hafez al-Assad, head of the Syrian Baath Party, imposed in the country a secretive, paranoid regime where even the slightest suspicion of dissent could land one in jail or worse.
One journalist, who met with Assad on several occasions before and after war broke out in 2011, told Agence France-Presse Assad is a "unique and complex figure".
Deadly crackdown
But his initial image as a reformer quickly evaporated as authorities arrested and jailed academics, intellectuals and other members of what was then known as the Damascus Spring movement.
When the Arab Spring reached Syria in March 2011, peaceful demonstrations broke out calling for change.
Assad, who was also commander-in-chief of the armed forces, responded by ordering a brutal crackdown on the protesters and civil war swiftly ensued.
Throughout the war, which killed more than 500,000 people and displaced half the population, Assad's position on the demonstrators and the opposition did not change.
To Syria and to the world, he justified the bombings and military campaigns as a war on "terrorists".
Meanwhile, his security apparatus enforced a brutal system of imprisoning dissidents in a network of detention centres and jails dotted around the country that have become notorious for abuses.
He was the subject of countless cartoons by dissident artists depicting him as a killer, not least in the aftermath of the 2013 chemical attacks on rebel bastions around Damascus.
What led to the fall of Assad?
Syria's opposition militias sensed an opportunity to loosen Assad's grip on power when, about six months ago, they communicated to Turkey plans for a major offensive and felt they had received its tacit approval, news agency Reuters reported.
Launched barely two weeks ago, the operation's speedy success in achieving its initial goal — seizing Syria's second city, Aleppo — took almost everybody by surprise.
The lightning advance relied on an almost perfect alignment of stars for the forces opposed to Assad: his army was demoralised and exhausted; his main allies, Iran and Lebanon's Hezbollah, were severely weakened by conflict with Israel; and his other key military supporter, Russia, was distracted and losing interest.
Syrians living in Greece wave Syrian opposition flags as they gather to celebrate the rebel takeover of the Syrian capital in Athens. Source: EPA / Alexander Beltes
Distracted by wars elsewhere, his military allies Russia, Iran, and Lebanon's Hezbollah failed to mobilise the kind of decisive firepower that had propped him up for years.
Syria's weak armed forces were unable to resist. A regime source told Reuters that tanks and planes were left with no fuel because of corruption and looting — an illustration of just how hollowed out the Syrian state had become.
Over the past two years morale had severely eroded in the army, said the source, who requested anonymity because of fear of retribution.
Aron Lund, a fellow at Century International, a Middle-East focused think-tank, said the HTS-led coalition was stronger and more coherent than any previous rebel force during the war, "and a lot of that is Abu Mohammed al-Golani’s doing". But, he said, the regime's weakness was the deciding factor.
"After they lost Aleppo like that, regime forces never recovered and the more the rebels advanced, the weaker Assad’s army got," he said.
The pace of the rebel advances, with Hama being captured on 5 December and Homs falling on or around Sunday at the same time government forces lost Damascus, exceeded expectations.
Bassam Al-Kuwatli, president of the Syrian Liberal Party, a small opposition group said: "There was a window of opportunity but no one expected the regime to crumble this fast. Everyone expected some fight."
