Who is Abu Mohammed al-Golani, leader of Syria's surprise insurgency?

From leader of the Syrian branch of al-Qaeda to commander-in-chief of militant group Hayat Tahrir al-Sham (HTS), Abu Mohammed al-Golani has spent the past dozen years carefully polishing his public image, including distancing himself from al-Qaida, in order to win over international governments and Syria's religious and ethnic minorities.