Khartoum is the center for commerce and government; Omdurman is the official capital; and North Khartoum is the industrial center, home to 70 percent of Sudan's industry. Six percent are Beja, 2 percent are foreign, and the remaining 1 percent are composed of other ethnicities. These include the Jamala and the Nubians in the north; the Beja in the Red Sea Hills; and several Nilotic peoples in the south, including the Azande, Dinka, Nuer, and Shilluk. There are more than one hundred different indigenous languages spoken in Sudan, including Nubian, Ta Bedawie, and dialects of Nilotic and Nilo-Hamitic languages.
It consists of three horizontal stripes: red, representing the blood of Muslim martyrs; white, which stands for peace and optimism; and black, which represents the people of Sudan and recalls the flag flown by the Mahdi during the 1800s.
It has a green triangle at the left border, which symbolizes both agriculture and the Islamic faith.
During the 1800s, the slave trade became a growing business in the region.
There had long been a system of domestic slavery, but in the nineteenth century, the Egyptians began taking Sudanese slaves to work as soldiers.
The northern part of the country is desert, spotted with oases, where most of the population is concentrated.
To the east, the Red Sea Hills support some vegetation. The southern region includes grasslands, and along the border with Uganda the Democratic Republic of the Congo, dense forests.
Several hundred years later, in 641, the Arabs arrived, bringing the Islamic faith with them.
They signed a treaty with the Christians to coexist in peace, but throughout the next seven centuries, Christianity gradually died out as more Arabs immigrated to the area and gained converts.
, when the city of Meroe was ransacked by the Ethiopians.
At about this time, three Christian kingdoms—Nobatia, Makurra, and Alwa—came into power in the area.
In the Middle Ages, Arabs named the area that is present-day Sudan "Bilad al-Sudan," or "land of the black people." The north is primarily Arab Muslims, whereas the south is largely black African, and not Muslim.