In 1881, a religious leader named Muhammad Ahmad proclaimed himself the Mahdi ("guided one") and began a war to unify the tribes in western and central Sudan. His followers took the name "Ansars" ("followers") which they continue to use today, in association with the single largest political grouping, the Umma Party (once led by a descendant of the Mahdi, Sadiq al Mahdi). Taking advantage of conditions resulting from Ottoman-Egyptian exploitation and maladministration, the Mahdi led a nationalist revolt culminating in the fall of Khartoum on 26 January 1885. The interim governor-general of the Sudan, the British Major-General Charles George Gordon, and many of the fifty thousand inhabitants of Khartoum were massacred.