The Bir Tawil area came under Egyptian administration in 1902, because it was grazing land of the Ababda tribe based near Aswan, Egypt. At the same time, the Hala'ib Triangle north of latitude 22° north, and northeast of the area, came under Sudanese administration, because the tribes of this area were based in Sudan. The two "triangles" border at one point, a quadripoint.
In 1899, when the United Kingdom held hegemony in the area, the Anglo-Egyptian Condominium Agreement for Sudan set the border between the territories at the 22nd parallel. However, in 1902 the UK drew a separate "administrative boundary," under which a triangle of land north of the parallel was placed under Sudanese administration, because its inhabitants were closer to Khartoum than Cairo, both geographically and culturally. The area thus became the responsibility of the British Governor in Khartoum.
Egypt claims the original border from 1899, the 22° north circle of latitude, which would place the Hala'ib Triangle within Egypt and the Bir Tawil area within Sudan. Sudan however claims the administrative border of 1902, which would put Hala'ib within Sudan, and Bir Tawil within Egypt. As a result, both states claim the Hala'ib Triangle and neither claims the much less valuable Bir Tawil area, which is only a tenth the size and is landlocked. There is no basis in international law for Sudan or Egypt to claim both territories, and it would be difficult if not impossible for any third state to claim the area, since it is accessible only through Sudan or Egypt. As a result Bir Tawil is one of the few land areas of the world which is not claimed by any state.