History of Sudan
The modern Republic of Sudan was formed in 1956 and inherited its boundaries from Anglo-Egyptian Sudan, established in 1899. For times predating 1899, usage of the term "Sudan" for the territory of the Republic of Sudan was somewhat anachronistic, and may have referred to the more diffuse concept of the Sudan.
Hala'ib Triangle
In 1899, when the United Kingdom held hegemony in the area, the Anglo-Egyptian Condominium Agreement for Sudan set the political boundary between the territories at the 22nd parallel. However, in 1902 the British drew a separate "administrative boundary," which assigned administration of the territory of the Ababda tribe south of the 22-degree latitude line to Egypt, and gave to Sudan the grazing land of the Beja tribe north of the line to administer. The Sudan-administered territory comprised about 18,000 km, including the towns of Hala'ib and Abu Ramad. When Sudan became independent in 1956, Egypt regarded the latitude 22° territorial boundary of 1899 as the border between the two countries, while Sudan held to the claimed 1902 administrative boundary. As a result, both Egypt and Sudan claim sovereignty over the territory. Conversely, the area south of the line which had been administered by Egypt, Bir Tawil, is a "terra nullius", claimed by neither country.