Eastern part of the Sudanese region, once known as Egyptian Sudan and became the condominium of Egypt and Great Britain by a convention signed between the two governments in 1899. Anglo-Egyptian Sudan borders N. with Egypt along 220 parallel, to E. with the Red Sea and then with Italian East Africa, to Sudan with Kenm, with Uganda and with the Belgian Congo about 4 ° lat. N., to the West with French Equatorial Africa and for a short distance with Libya: it measures 1900 km. in a straight line from Sudan to N., and 1600 km. from E. to O., with an area of 2,693,600 sq. km., and connects the English protectorate of Uganda with Egypt, also under English control, thus ensuring Great Britain the entire course of the Nile (v.), from its sources in Lake Victoria Nyanza to its mouths.
The country, in its NE sector. where it goes as far as the Red Sea, it is mountainous, and can be reached there with Jebel Erba 2280 m. From these reliefs of the Etbai chain, which in Sudan continue with those of the Ethiopian Plateau, the ground gradually descends to the West as far as the Nile, which however in some stretches, as near Berber at the 5th cataract, comes very close to the mountains and carves them. On the left of the river there are vast plains, bumpy by the modest reliefs of Kordofan and by the more marked ones of Darfur (Jebel Marra, 1500-1800 m.), While in the SW., Beyond the valley of the Bahr el-Ghazal, the ground rises gradually up to altitudes of 600 m. at the watershed between the Nile and the Congo. Geologically (see africa: Geology) Sudan is constituted in the Etbai chain and in the area at the foot of the Ethiopian plateau, of crystalline schists and granite rocks, with gold-bearing quartz veins; in the western part (Nubia), on the other hand, the so-called Nubian sandstones emerge, of Cretaceous or older age, which extend with similar facies in Kordofan, Darfur and in the southern and western Bahr el-Ghazal basin; the bottom of this and of the Nilotic valley is occupied by alluvial deposits.
Given its geographical position, the great distance from the sea and the modest elevation, the Anglo-Egyptian Sudan has a tropical, continental, very hot climate: in Khartoum there are two maximums, one in April-May (45 °) and the other in September. (43 °). At N. di Berher the country is an arid desert, a southern continuation of the Egyptian deserts, and, except along the Nile, which is the only stream, and in the valley floor, there is no trace of vegetation. Between the 20th and 17th parallel, first in the mountains of the eastern region, then in the hilly or flat regions of the west, a landscape of steppe begins with groups of umbrella-shaped acacias and grasslands, which however dry up entirely when they cease of the rains, which fall inland from mid-June to September, while in the coastal area on the Red Sea the few violent showers occur between August and January. As we proceed towards the south, the rains become more abundant (200-400 mm.) And less precarious, the vegetation becomes more luxuriant, even wooded in the Kordofan and in the Bahr el-Ghazal, and in the Nile, which crosses the whole village from Sudan to N., the waters of the Bahr el-Ghazal run from the left, those of the Atbara, the Gasc, the Sobat from the right. In the southernmost area they fall up to 800 mm. of rain and more; the White Nile is flanked by vast marshes full of grasses, which sometimes form solid rafts and bars hindering the vegetation (even wooded in the Kordofan and in the Bahr el-Ghazal, and to the Nile, which crosses the whole country from Sudan to N., the waters of the Bahr el-Ghazal from the left, those of the Atbara, the Gasc, the Sobat from right. In the southernmost area they fall up to 800 mm. of rain and more; the White Nile is flanked by vast marshes full of grasses, which sometimes form solid rafts and bars hindering the vegetation (even wooded in the Kordofan and in the Bahr el-Ghazal, and to the Nile, which crosses the whole country from Sudan to N., the waters of the Bahr el-Ghazal from the left, those of the Atbara, the Gasc, the Sobat from right. In the southernmost area they fall up to 800 mm. of rain and more; the White Nile is flanked by vast marshes full of grasses, which sometimes form solid rafts and bars hindering the vegetation (sudd), and the country, covered with forests and ponds, has a pestilent climate.
African wildlife is abundant everywhere, so Anglo-Egyptian Sudan is a land of big game: monkeys, elephants, rhinos, buffaloes, various birds swarm in the forests of the Bahr el-Ghazal and the Nile, hippos, crocodiles, water birds, in swamps and rivers; lions, leopards, giraffes, antelopes, in the grasslands and sparse forests of Kordofan and middle Sudan; ostriches, monitor lizards, snakes, in the arid steppe and deserts of the north. The tsetse fly and mosquitoes are dangerous agents transmitting diseases: also harmful are the horseflies parasites of livestock, termites, locusts, infests to agriculture.
The northern part of Anglo-Egyptian Sudan is inhabited by tribes almost all of Arab origin, who have embraced Islam, while retaining rites that are in contradiction with the Koran. The non-Muslim tribes almost all belong to the Nilotic group. The main ones are: the Scilluk, the Luo, erroneously known as Jur, the Agnuak, the Dinca, the Nuer, the Bari and Lotuko tribes, the Nuba, the populations of Darfur, the Bongo, the Mittu, the Madi, the Belanda. The Asandè, commonly known by the nickname of Niam-Niam, do not belong to the Nilotic group and only a part of them occupy the territory of Anglo-Egyptian Sudan. Nilotic are also some tribes of Uganda: the Acholi, the Lango and the Gialuo of Kenya. All these tribes of common origin have preserved very archaic elements in the material and spiritual culture.
The iron spear, which is thrown. it is the most widespread weapon among the Nilotic populations, but it is relatively recent. The Scilluk, the Dinca, the Nuer still have wooden and bone spears with the iron spear. The bumerang is rare, but it still survives. The use of the sling is rare. The arch is still in use by all Nilotic populations. The shape and size of the shield, which is generally made of leather, are various. A very archaic form of defense still survives, consisting of a stick that serves to parry the blows of the club. This, which is thrown, is almost always of wood, sometimes it is only a root; the stone club is rare.
Men go naked or wear skin that they pass over their shoulder, women wear a piece of skin that reaches down to their knees. True Nilotics take great care of their hair and wear ivory bracelets around their biceps.
All the tribes practice hunting, fishing and agriculture, livestock has less importance in daily life: the Dinca, however, are passionate breeders, while the Luo and even more the Agnuak are mainly farmers. Recent studies have questioned what was previously believed that the Nilotics were originally shepherds. The question, however, is not easy to solve because the economy of the Nilotics suffered in the century. XX strong changes.