The Mahdia revolution was a result of the cruelty and injustice of Turkish rule. It manifested itself in religious terms to a reformation and renewal of the faith as expressed by its leader, Mohammed Ahmed al-Mahdi, a Sufi religious figure.
In June 1881, the Mahdi called on the people to support him in overthrowing Turkish rule. The revolution began at Aba Island, on the White Nile. Many gathered at the island in support and to fight the first victorious battle of the revolution. The Mahdi sought refuge to the west, at Gadir in the Nuba Mountains, where, in 1882, he defeated a force of six hundred soldiers led by Yousif Shalali.
By September 1882, the Mahdists controlled all of Kordofan, and at Shaykan on 5 November 1883, they destroyed an Egyptian army of ten thousand men under the command of a British colonel. After Shaykan, the Turks’ defeat was assured, and not even the leadership of Colonel Charles Gordon, who was hastily sent to Khartoum, could save the situation for Egypt. On 26 January 1885, the Mahdists captured Khartoum and killed Colonel Gordon.
The Mahdi died in June 1885, and he was succeeded by the Khalifa Abdallahi ibn Muhammad. The khalifa’s first task was to secure his own position against a conspiracy by the Mahdi’s relatives. He established a highly centralized administrative system—essentially military rule by a tyrant. This way of dealing with the country’s affairs differed little from the Turkish occupation and led to several mutinies and broad opposition to his rule. Some tribes of central and western Sudan revolted against the khalifa; the rebellions were put down ruthlessly.
The foreign policy of the khalifa was based on spreading Mahdism by military means. He sent his forces to Darfur, and in the east, defeated the Ethiopians. In southern Sudan, he was driven from the upper Nile in 1897 by the Congo Free State forces. On the Egyptian frontier, in the north, his armies met their worst defeat at Tushki in August 1889, when an Anglo-Egyptian army under General F.W. Grenfell destroyed Abd al-Rahman al-Nujumi’s army. British forces defeated the Mahdist state on 2 September 1898, at the Battle of Omdurman, where thousands of Sudanese were massacred.