The Isis caliphate is no more. Four years after its fighters captured large swathes of Iraq and Syria and declared its intention to spread jihad around the world, the terror group no longer holds any territory.

But as one extremist Islamic state falls, another one endures. Over the past few years, a group that was formerly part of al-Qaeda has cemented its power in northern Syria and now rules over some 3 million people.

After forcing out rival rebel groups in Idlib earlier this year, Hayat Tahrir al-Sham(HTS) has moved to impose its control over all institutions in the province. A university with more than 6,000 students has become the latest battleground in its quest for dominance.