BEIRUT (Reuters) -As the commander of al Qaeda's franchise in the Syrian civil war, Abu Mohammed al-Golani was a shadowy figure who kept out of the public eye, even when his group became the most powerful faction fighting to topple Bashar al-Assad.

Syrian pro-democracy moderates can’t shake off their memories of when al-Golani first rose to prominence in chaotic war-torn northern Syria, where he’d been dispatched to set up Jabhat al-Nusra, a Syrian branch of al Qaeda.