Which terroristic group has been a major force in the conflicts in Iraq Syria and Yemen

The major terroristic group that has been active in the conflicts in Iraq, Syria, and Yemen is the Islamic State of Iraq and Syria (ISIS), also known as the Islamic State (IS) or Daesh. They have conducted numerous acts of terrorism and established a self-proclaimed caliphate in parts of Iraq and Syria. While their influence has significantly diminished in recent years, they continue to pose a threat in the region.