Sudan (suːˈdɑːn or suːˈdæn ; Sūdān), officially the Republic of the Sudan (Jumhūriyyat as-Sūdān), is a country in Northeast Africa. It borders the Central African Republic to the southwest, Chad to the west, Egypt to the north, Eritrea to the northeast, Ethiopia to the southeast, Libya to the northwest, South Sudan to the south, and the Red Sea. It has a population of 45.7 million people as of 2022 and occupies 1,886,068 square kilometres (728,215 square miles), making it Africa's third-largest country by area and the third-largest by area in the Arab League. It was the largest country by area in Africa and the Arab League until the secession of South Sudan in 2011; since then both titles have been held by Algeria. Its capital city is Khartoum, and its most populous city is Omdurman (part of the metropolitan area of Khartoum).
History witnessed the Kingdom of Kerma ( 2500–1500 BC), the Egyptian New Kingdom ( 1500 BC–1070 BC), and the Kingdom of Kush ( 785 BC–350 AD). After the fall of Kush, the Nubians formed the three Christian kingdoms of Nobatia, Makuria, and Alodia. Between the 14th and 15th centuries, most of Sudan was gradually settled by Arab nomads. From the 16th to the 19th centuries, central and eastern Sudan were dominated by the Funj sultanate, while Darfur ruled the west and the Ottomans the east. In 1811, Mamluks established a state at Dunqulah as a base for their slave trading. Under Turco-Egyptian rule of Sudan after the 1820s, the practice of trading slaves was entrenched along a north–south axis, with slave raids taking place in southern parts of the country and slaves being transported to Egypt and the Ottoman empire. From the 19th century, the entirety of Sudan was conquered by the Egyptians under the Muhammad Ali dynasty. Religious-nationalist fervour erupted in the Mahdist Uprising in which Mahdist forces were eventually defeated by a joint Egyptian-British military force. In 1899, under British pressure, Egypt agreed to share sovereignty over Sudan with the United Kingdom as a condominium.