History of Sudan association with the single largest political grouping, the [[National Umma Party Sudan|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. The Mahdi died in June 1885. He was followed by [[Abdallahi ibn Muhammad]], known as the [[Caliph|Khalifa]], who began an expansion of Sudan's area into Ethiopia. Following
Siege of Khartoum its lowest. The relief expedition was attacked at Abu Klea on 17 January, and two days later at Abu Kru. Though their square was broken at Abu Klea, the British managed to repel the Mahdists. The Mahdi, hearing of the British advance, decided to press the attack on Khartoum. On the night of 25–26 January an estimated 50,000 Mahdists attacked the city wall just before midnight. The Mahdists took advantage of the low level of the Nile, actually crossing it on foot, and rushed around the wall on the shores of the river and into the town. The details of