Sudan, Republic of, republic in north-eastern Africa, the largest nation of the African continent. It is bordered on the north by Egypt; on the east by the Red Sea, Eritrea, and Ethiopia; on the south by Kenya, Uganda, and the Democratic Republic of the Congo; and on the west by the Central African Republic, Chad, and Libya. Sudan has a total area of 2,505,800 sq km (967,490 sq mi). Khartoum is the capital and largest city.