In popular Muslim belief, a spiritual and temporal leader who will rule before the end of the world and restore religion and justice. The title has been claimed by various leaders; the most widely known of these was Muhammad Ahmad of Dongola in Sudan (1843–85), who proclaimed himself Mahdi in 1881 and launched a political and revolutionary movement which captured Khartoum and overthrew the Egyptian regime. For Shiite Muslims the title Mahdi refers to the twelfth imam.