al-Julani is the leader of Jabhat Fateh al-Sham, the once al-Qaeda affiliated organization known as Jabhat al-Nusra, or the al-Nusra Front.
ISIS refers to his followers as “apostates of al-Julani.”
Both ISIS and Jabhat Fateh al-Sham were once branches of al-Qaeda. They are now at war with each other. Earlier this week, the leader of al-Qaeda, Ayman al-Zawahiri, released an audio message directed at Abu Bakr al-Baghdadi, the leader of ISIS, calling him a liar.
According to Vocativ, al-Zawahiri admonished ISIS for attacking Muslim civilians, specifically Shiites.