The sudden collapse of Bashar al-Assad's rule over Syria marks the culmination of a nearly 14-year uprising and a key moment in a civil war that killed hundreds of thousands of people, displaced half the population and drew in outside powers.
This is how it unfolded:
* 2011 - The first protests against Assad quickly spread across the country, and are met by security forces with a wave of arrests and shootings.
Some protesters take up guns and military units defect as the uprising becomes an armed revolt that will gain support from Western and Arab countries and Türkiye.
* 2012 - A bombing in Damascus is the first by al-Qaeda's new Syrian affiliate, the Nusra Front, which gains in power and starts crushing groups with a nationalist ideology.
World powers meet in Geneva and agree on the need for a political transition, but their divisions on how to achieve it will foil years of UN-sponsored peace efforts.
Assad turns his air force on opposition strongholds, as the fighters gain ground and the war escalates with massacres on both sides.
* 2013 - Lebanon's Hezbollah helps Assad to victory at Qusayr, halting opposition momentum and showing the Iran-backed group's growing role in the conflict.
Washington has declared chemical weapons use a red line, but a gas attack on opposition-held eastern Ghouta near Damascus kills scores of civilians without triggering a US military response.
* 2014 - The ISIS group suddenly seizes Raqqa in the northeast and swathes more territory in Syria and Iraq.
The opposition figters in the Old City of Homs surrender, agreeing to move to an outer suburb - their first big defeat in a major urban area and a precursor to future "evacuation" deals.
Washington builds an anti-ISIS coalition and starts air strikes, helping Kurdish forces turn the extremist tide but creating friction with its ally Türkiye.
* 2015 - With better cooperation and more arms from abroad, opposition groups gain more ground and seize northwestern Idlib, but extremist militants are taking a bigger role.
Russia joins the war on Assad's side with air strikes that turn the conflict against the opposition for years to come.
* 2016 - Alarmed by Kurdish advances on the border, Türkiye launches an incursion with allied opposition groups, making a new zone of Turkish control.
The Syrian army and its allies defeat the opposition in Aleppo, seen at the time as Assad's biggest victory of the war.
The Nusra Front splits from al-Qaeda and starts trying to present itself in a moderate light, adopting a series of new names and eventually settling on Hayat Tahrir al-Sham (HTS).
* 2017 - Israel acknowledges air strikes against Hezbollah in Syria, aiming to degrade the growing strength of Iran and its allies.
US-backed, Kurdish-led forces defeat ISIS in Raqqa. That offensive, and a rival one by the Syrian army, drive the extremist group from nearly all its land.
* 2018 - The Syrian army recaptures eastern Ghouta, before quickly retaking the other opposition enclaves in central Syria, and then the opposition’s southern bastion of Daraa.
* 2019 - ISIS loses its last scrap of territory in Syria. The US decides to keep some troops in the country to prevent attacks on its Kurdish allies.
* 2020 - Russia backs a government offensive that ends with a ceasefire with Türkiye that freezes most front lines. Assad holds most territory and all main cities, appearing deeply entrenched. The opposition holds the northwest. A Türkiye-backed force holds a border strip. Kurdish-led forces control the northeast.
* 2023 - The Hamas attack on Israel on Oct. 7 triggers fighting between Israel and Hezbollah in Lebanon, ultimately reducing the group's presence in Syria and fatally undermining Assad.
* 2024 – The opposition launches a new assault on Aleppo. With Assad's allies focused elsewhere his army quickly collapses. Eight days after the fall of Aleppo the opposition fighters have taken most major cities and enter Damascus, driving Assad from power.
