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
Khartoum forces. The Organisation of African Unity summit of 18–22 July 1978 was held in Khartoum, during which Sudan was awarded the OAU presidency. The African Union summit of 16–24 January 2006 was held in Khartoum. The Arab League summit of 28–29 March 2006 was held in Khartoum, during which the Arab League awarded Sudan the Arab League presidency. On 10 May 2008, the Darfur rebel group, Justice and Equality Movement, moved into the city, where they engaged in heavy fighting with Sudanese government forces. Their soldiers included minors, and their goal was to topple Omar al-Bashir's government, though the Sudanese