What is Hayat Tahrir al-Sham? And how did the Islamist group evolve into a key player in Syria’s civil war?

Anti-Assad fighters stationed at the airport in Aleppo on Dec. 2, 2024. Omar Haj Kadour/AFP via Getty Images

A major offensive has seen rebel groups in Syria retake the country’s second city, Aleppo – and demonstrated the growing prominence of the Islamist group Hayat Tahrir al-Sham in the 13-year-long civil war.

The surprise advance was led by members of Hayat Tahrir al-Sham, fighting alongside Turkish-backed groups opposing the rule of President Bashar al-Assad.