Syrian rebel forces led by Hayat Tahrir al-Sham, or HTS, declared they had ousted President Bashar al-Assad and he had fled Damascus on Sunday. But what is HTS, and how did it rock the long-simmering tensions in Syria? HTS is a Sunni Islamist militant and political group that traces its roots to the beginning of the Syrian civil war.

Sham, or HTS, that took over Syria and ousted President Bashar al-Assad, has yet to show how it plans to govern the country torn by more than a decade of civil war. CBS News contributor Sam Vinograd breaks down what's known about the opposition group in power.