 Complete the following phrase:  Muhammad Ahmad bin Abd Allah ; 12 August 1844  22 June 1885 was a Nubian Sufi religious leader of the Samaniyya order in Sudan who, as a youth, studied Sunni Islam. In 1881, he claimed to be the Mahdi. He led a successful war against Ottoman-Egyptian military rule in Sudan and achieved a remarkable victory over the British, in the 