Muhammad Ahmad bin Abd Allah ( Arabic : محمد أحمد المهدي ) ( August 12 , 1844 - June 22 , 1885 ) was a religious leader of the Samaniyya order in Sudan who , on June 29 , 1881 , proclaimed himself as the Mahdi or messianic redeemer of the Islamic faith .
Muhammad Ahmad bin Abd Allah ( 12 August 1845 - 22 June 1885 ) was a religious leader of the Sufi Samaniyya order in Sudan .