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.
Demographics of South Sudan
At the time of Sudan’s independence in 1956, Northern Moslems were appointed to senior positions in the south. During the 1970, the Unregistered Land Act ended the last remnants of colonial administrative systems, which were replaced by central-state system of leasing land for large farming operations. “These land grabs by the government were also the reasons why so many farmers and pastoralists [herders] that saw their land assimilated into mechanized farming schemes, or simply registered in someone else’s name, joined the Sudan People’s Liberation Movement (SPLM) in the late 1980s”