The terrorist organization Hayat Tahrir al-Sham (HTS) with its leader Abu Mohammed al-Jolani has become at the forefront of the current war in Syria. HTS advanced from their home base in the north-western province of Idlib into the big cities of Hama and Homs, finally taking control of the capital Damascus. The group is not the only one to take advantage of the fall of Bashar al Assad’s regime. Other rebel factions are also active there as one of them is the Islamic State (ISIS) which has an opportunity to revive again. It is important to note that actually HTS originated from Jabhat al-Nusra which was formed in 2012 by ISIL (later ISIS). A year later it split from ISIL and pledged allegiance to Al-Qaeda. In a similar way the new formation broke ranks with Al-Qaeda and started its own agenda. This paper looks at the current relations of Islamic State and Hayat Tahrir al-Sham in Syria and analyzes if they can coexist together or shall engage in conflict thereafter. Eventually all enemies of Assad now have to choose between peaceful negotiations or throwing the country into chaos and civil war. The study is divided into two parts. The first one provides a historical overview of how HTS emerged from ISIS and then diverged from it. The second section carries out implications on what role they will play from now on.