In Twelver Shiism, the designation of four successive persons to act as deputies of the Hidden Imam. When the twelfth imam went into occultation, a lesser occultation period followed in which four successive persons claimed to be his deputies. In 944 the last one declared that there would be no more specific representatives until the Hidden Imam returned, marking the beginning of the period of greater occultation. The only figure since then to claim special deputy status was the founder of the nineteenth-century Bab movement in Iran. Ayatollah Khomeini concentrated the general deputyship in himself, rendering him the de facto if not de jure vicegerent of the Hidden Imam.