Abu Mohammed al-Julani heads Hayat Tahrir al-Sham (HTS)- the most powerful armed rebel group in Syria. The 42-year-old, who led the offensive that ended Assad family's 50-year-rule, fought for Al-Qaeda against US in Iraq. He founded Al-Qaeda's Syrian branch and named it Jabhat al-Nusr, but severed ties with Al-Qaeda in 2016. US had placed a $10 million bounty on al-Julani.