How the Syrian rebels quelled by iron-fisted Assad came back to topple him - explainer

Syria's Bashar al-Assad used Russian and Iranian firepower to beat back rebel forces during years of civil war but never defeated them, leaving him vulnerable to their breathtaking advance when his allies were distracted by wars elsewhere.

President for 24 years, Assad flew out of Damascus for an unknown destination early on Sunday, two senior army officers told Reuters. Rebels declared the city "free of the tyrant Bashar al-Assad." A half-century of Assad family rule was over, army command told officers, according to a Syrian officer.

Statues of Assad's father and brother were toppled in cities taken by the rebels, while pictures of him on billboards and government offices were torn down, stamped on, burned, or riddled with bullets.

Assad became president in 2000 after his father Hafez died, preserving the family's iron-fisted rule and the dominance of their Alawite sect in the Sunni Muslim-majority country and Syria's status as an Iranian ally hostile to Israel and the US.

Shaped in its early years by the Iraq war and crisis in Lebanon, Assad's rule was defined by civil war, which spiraled out of the 2011 Arab Spring, when Syrians demanding democracy took to the streets.

Branded an "animal" in 2018 by US President Donald Trump for using chemical weapons - an accusation he denied - Assad outlasted many of the foreign leaders who believed his demise was imminent in the early days of the conflict when he lost swathes of Syria to rebels.

Helped by Russian air strikes and Iranian-backed militias, he clawed back much of the lost territory during years of military offensives, including siege warfare condemned as "medieval" by UN investigators.

With his opponents largely confined to a corner of northwestern Syria, he presided over several years of relative calm, though large parts of the country remained out of his grasp and the economy was shackled by international sanctions.

Assad re-established ties with Arab states that once shunned him but remained a pariah to much of the world and never managed to revive the shattered Syrian state, whose armed forces swiftly retreated in the face of rebel advances.

He has not delivered any public remarks since insurgents took Aleppo a week ago but said in a call with Iran's president that the escalation sought to redraw the region for Western interests, echoing his view of the revolt as a foreign-backed conspiracy.

Justifying his response to the insurgency in its early stages, Assad compared himself to a surgeon. "Do we say to him: 'Your hands are covered in blood?' Or do we thank him for saving the patient?" he said in 2012.

Early in the conflict, as rebels seized town after town, Assad was confident.

"We will hit them with an iron fist, and Syria will return to how it was," he told soldiers after taking back the town of Maaloula in 2014.

He delivered on the first pledge but not the second. Years later, large parts of Syria remained outside state control, cities were flattened, the death toll topped 350,000, and more than a quarter of the population had fled abroad.

Red lines

Assad was backed by those Syrians who believed he was saving them from hardline Sunni Islamists.

As al-Qaeda-inspired insurgent groups gained prominence, this fear resonated among minorities. Rebel forces sought to assure Christians, Alawites, and other minorities they would be protected as they advanced this week.

Assad clung to the idea of Syria as a bastion of secular Arab nationalism even as the conflict appeared ever more sectarian. Speaking to Foreign Affairs in 2015, he said Syria's army was "made up of every color of Syrian society."

But to his opponents, he was fueling sectarianism.

The conflict's sectarian edge was hardened by the arrival of Iranian-backed Shi'ite fighters from across the Middle East to support Assad, and as Sunni Muslim-led states, including Turkey and Qatar, backed the rebels.

Assad's value to Iran was underscored by a senior Iranian official who declared in 2015 that his fate was a "red line" for Tehran.

While Iran stood by Assad, the United States failed to enforce its own "red line" - set by President Barack Obama in 2012 against the use of chemical weapons.

UN-backed investigations have concluded Damascus used chemical weapons.

A sarin gas attack on the rebel-held Ghouta in 2013 killed hundreds, but Moscow brokered a deal for Syria's chemical weapons to be destroyed, averting a US. response. Still, poison gas continued to hit rebel areas, with a 2017 sarin attack prompting Trump to order a cruise missile response.

Assad has denied accusations the state was to blame.

He similarly denied the army had dropped barrel bombs packed with explosives that caused indiscriminate destruction. He appeared to make light of the accusation in a BBC interview in 2015, saying: "I haven't heard of the army using barrels, or maybe, cooking pots."

He also dismissed tens of thousands of photos showing torture of people in government custody as being part of a Qatar-funded plot.

As fighting died down, Assad accused Syria's enemies of economic warfare.

But while he remained a pariah to the West, some Arab states that once backed his opponents began opening doors to him. A beaming Assad was greeted by leaders of the United Arab Emirates during a visit there in 2022.

 Eye doctor

Assad often presented himself as a humble man of the people, appearing in films, driving a modest family car, and in photographs of his wife visiting war veterans in their homes.

He took office in 2000 after his father's death but had not always been destined for the presidency.

Hafez had groomed another son, Bassel, to succeed him. But when Bassel died in a 1994 car crash, Bashar was transformed from an eye doctor in London - where he studied as a postgraduate - to heir apparent.

Upon becoming president, Assad seemed to adopt liberal reforms, painted optimistically as "the Damascus spring."

He released hundreds of political prisoners, made overtures to the West, and opened the economy to private companies.

His marriage to British-born former investment banker Asma Akhras - with whom he had three children - helped foster hopes he could take Syria down a more reformist path.

High points of his early dalliance with Western leaders included attending a Paris summit where he was a guest of honor at the annual Bastille Day military parade.

But with the political system he inherited left intact, signs of change quickly dried up.

Dissidents were jailed, and economic reforms contributed to what US diplomats described, in a 2008 embassy cable released by WikiLeaks, as "parasitic" nepotism and corruption.

While the elite did well, drought drove the poor from rural areas to slums where the revolt would blaze.

Tensions built with the West after the US-led invasion of Iraq in 2003 turned the Middle Eastern power balance on its head.

The assassination of Lebanon's Rafik al-Hariri in Beirut in 2005 prompted Western pressure that forced Syria's withdrawal from its neighbor. An initial international probe implicated senior Syrian and Lebanese figures in the killing.

While Syria denied involvement, former Vice President Abdel-Halim Khaddam said Assad had threatened Hariri months earlier - an accusation Assad also denied.

Fifteen years later, a UN-backed court found a member of the Iranian-backed terror group Hezbollah guilty of conspiring to kill Hariri. Hezbollah, an Assad ally, denied any role.