Abdallahi ibn Muhammad
In March 1881, Muhammad Ahmad, living on Aba Island on the White Nile, before his "inner circle" (which included Abdallahi ibn Muhammad, who would become known as "the Khalifa"), announced that he was the Mahdi. He based this off of a dream he had where he was visited by the Prophet Muhammad and Jesus Christ. The Governor-General of the Sudan, Ra'uf Pasha, soon sent Mohammad Bey Abu Sa'ud to investigate the situation. Arriving on Aba Island on August 7, 1881, Abu Sa'ud requested that Muhammad Ahmad come to Khartoum (the capital of Sudan) to meet with the Governor-General. The Mahdi refused and Abu Sa'ud warned him that he "must give up his claim to be the Mahdi" and then left the island.