Reformers of Hizb-ut-Tahrir is the smallest of four factions of the radical Islamist Hizb-ut-Tahrir (“the Party of Liberation”), which has been outlawed in a number of nations that regard it as subversive and linked to terrorists. The overriding aim of this party and its various factions is to replace all existing governments with a global Islamic Caliphate under a single ruler, or Caliph.

According to Sheikh Omar Bakri Mohammed (the founder of Al Muhajiroun), Reformers of Hizb-ut-Tahrir’s American leader is Iyad Hilal. Hilal authored Studies in Usul ul Fiqh, a book about Islamic Shari’ah law that is featured prominently on the website of the British organization Islamic Truth Group, which has links to both Hizb-ut-Tahrir and Al Muhajiroun.  

The leader of Reformers of Hizb-ut-Tahrir’s operations in Germany, where Hizb-ut-Tahrir has been outlawed, is Dr. Tawfiq Mustafa.