The Ibāḍī movement, Ibadism or Ibāḍiyya, also known as the Ibadis (, al-Ibāḍiyyah), is a school of Islam dominant in Oman and Zanzibar. It is also found in Algeria, Tunisia, Libya and East Africa. The movement is said to have been founded 20 years after the death of the Muslim prophet Muhammad, predating both the Sunni and Shia denominations. Historians and a majority of Muslims believe that the denomination is a reformed sect of the Khawarij movement; Ibāḍīs, however, deny anything more than a passing relation to the Khawarij and point out that they merely developed out of the same precursor group.