The group behind these dramatic developments, Hayat Tahrir al-Sham (HTS), has held a consequential but checkered role in the country’s long-running civil war.

With its roots in the early days of Syria’s 2011 uprising, the Organization for the Liberation of Greater Syria swept down this week from its strongholds in the northwest countryside to take control of a vast swath of a country that had long been under the grip of Syrian President Bashar al-Assad’s forces.

But in recent years HTS has publicly disavowed international terrorism and tries to present a more moderate face, according to Charles Lister, the director of the Syria Program at the Middle East Institute think tank in Washington D.C.