Northeast Sudan, called Nubia in ancient times, was colonized (c.2000 BC) by Egypt as far as the fourth cataract of the Nile and ruled by the Cush Kingdom from the 8th century B.C. to the 4th. Meroe, near the fourth cataract of the Nile, was a center of trade and ironworking, and from there iron technology may have spread to other parts of Africa.
The main geographical feature of Sudan is the Nile River, which, with its tributaries (including the Atbara, Blue Nile, and White Nile rivers), traverses the country from south to north. The Nile system provides irrigation for strips of agricultural settlement for much of its course in Sudan and also for the Al Gezira plain, situated between the White Nile and the Blue Nile, just south of their confluence at Khartoum. In the extreme north, the Nile broadens into Lake Nasser, formed by the Aswan High Dam in Egypt.
From the 13th to the 15th cent. the region was increasingly infiltrated by peoples from the north; the states collapsed, and Nubia gradually became Muslim. The southern part of the modern Sudan continued to adhere to traditional African beliefs. Much of the north was ruled by the Muslim state of Funj from the 16th cent. until 1821, when it was conquered by armies sent by Muhammad Ali of Egypt.
The Egyptians founded (1823) Khartoum as their headquarters and developed Sudan's trade in ivory and slaves. Ismail Pasha (in office 1863–79) tried to extend Egyptian influence further south in Sudan, ostensibly to end the slave trade. This campaign, which was headed first by Sir Samuel Baker and then by Charles Gordon, provoked a complex revolt (1881) by the Mahdi (Muhammad Ahmad), who sought to end Egyptian influence and to purify Islam in Sudan. The Mahdists defeated Anglo-Egyptian punitive expeditions, and Britain and Egypt decided to abandon Sudan. Gordon, sent to evacuate the British and Egyptian troops, was killed by the Mahdists at Khartoum in early 1885. The Mahdi died in the same year, but his successor, the Khalifa Abdallahi, continued to build up the theocratic Mahdist state. In the 1890s the British decided to gain control of Sudan, and, in a series of campaigns between 1896 and 1898, an Anglo-Egyptian force under Herbert (later Lord) Kitchener destroyed the power of the Mahdists. Agreements in 1899 (reaffirmed by the Anglo-Egyptian treaty of 1936) established the government of the Anglo-Egyptian Sudan.
