Mutawakkilite Kingdom of Yemen
For Shi'a Muslims, the Imams are leaders of the Islamic community or ummah after the Prophet. The term is only applicable to the members of "Ahl al-Bayt", the family of the Islamic Prophet Muhammad, considered infallibles by Twelver Shia. The title was also used by the Zaidi Shia Imams of Yemen, who eventually founded the Mutawakkilite Kingdom of Yemen (1918–1970).