Its area is close to the Kassala province. Several concessions were made without compensation to appease Italy and out of fear of it. This cession was not permanent, but the annexed part was shown on maps with the inscription "1934 Ceded to Italy," meaning it was annexed to Italy in 1934. This part now falls within the Kingdom of Libya.

The northwestern border of Sudan is also a latitudinal border, north of latitude 15°40', approximately. The tribes do not pay attention to it, as sections of the Zaghawa, Kurban, and Bahdabat tribes cross it, along with some of the Kababish, into Chad, where they graze the rich Gizoo grasses in the winter. To the south, this line follows some watercourses that form the main settlement areas, such as Koji Kaja, and sometimes crosses them in Wadi Azum. Cattle are moved from one side to another. The Ba'isha, for example, who are considered Sudanese tribes, are forced by some of their sections to pay taxes twice, to the Sudanese government and the Chadian government. There is also migration along this border. While official procedures and customs are carried out on the main roads from Abeshé, it is practically impossible to control smuggling and illegal infiltration.

The agreement on the demarcation of the southwestern borders of Sudan went through several stages between Britain and the Congo Free State. The first stage was an agreement in May 1894, in which both parties agreed that Britain would lease to King Leopold II of the Congo Free State almost the entire Bahr el Ghazal province, and a part of this province. The duration of this lease was tied to the duration of Leopold's reign, in exchange for Belgium leasing to England a strip of land 25 km wide extending between Lake Tanganyika and Lake Nyasa.

The second stage was completed after numerous negotiations, which concluded with the signing of the May 1906 agreement. By this agreement, King Leopold ceded the area known as the Lado Enclave.