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 main Nile ("see map, upper right") as it zigzags through northern Sudan into Egypt at Lake Nasser. Khartoum is relatively flat, at elevation , as the Nile flows northeast past Omdurman to Shendi, at elevation about away. Under Köppen's climate classification system, Khartoum features a hot arid climate, with only the summer months seeing noticeable precipitation. The city averages a little over of precipitation per year. Based on annual mean temperatures, the city is one of the hottest major cities in the world. Temperatures routinely exceed in mid-summer. Its average annual high temperature is , with six months of the