HTS Who are the group that seized Aleppo?

For about five years, Hay'at Tahrir al-Sham has controlled the north-western Syrian province of Idlib, where it has set up what it calls the Syrian Salvation Government to administrate schools, clinics and courts for an estimated 4 million people.

- Jason Burke

Idlib provides a secure territorial base but also a steady stream of funding from taxes, as well as other resources.

The group's forces are reportedly well-trained but lightly equipped, though heavier weapons have been seized from Syrian government troops in the advances of recent days. HTS leads a rough coalition of ideologically aligned smaller factions, including groups made up of Uzbek, Tajik and Turkmen militants based in Syria for many years. There may be a "smattering" of veteran western European Islamists among them, analysts said.