Sudan (region) to the present-day country of Sudan, the western part of which forms part of the larger region, and from which South Sudan gained its independence in 2011. The Sudan region extends in some 5,000 km in a band several hundred kilometers wide across Africa. It stretches from the border of Senegal, through southern Mali (formerly known as French Sudan when it was a French colony), Burkina Faso, southern Niger, northern Nigeria, northern Ghana, southern Chad, the western Darfur region of present-day Sudan, and South Sudan. To the north of the region lies the Sahel, a more arid Acacia savanna region
Slavery in Sudan kingdoms' fall in 1504, the Ottomans conquered most of Nubia, while the Funj conquered much of modern day Sudan from Darfur to Khartoum ; the Funj began to use slaves in the army in the reign of Badi III (r. 1692-1711). Later, Egyptian slavers began raiding modern South Sudan. In particular, the ruler Muhammad Ali of Egypt attempted to build up an army of Southern Sudanese slaves with the aid of the Nubian slavers. Attempts to ban slavery were later attempted by colonial British authorities in 1899, after they conquered the region. According to British explorer (and abolitionist) Samuel Baker,