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.
History of South Sudan
In 1955, four months before Sudan achieved independence, the First Sudanese Civil War started, with aims of achieving representation and more regional autonomy. For seventeen years, the Sudanese government fought the Anyanya rebel army. In 1971, former army Lt. Joseph Lagu gathered all the guerilla bands under his South Sudan Liberation Movement (SSLM). This was the first time in the history of the war that the separatist movement had a unified command structure to fulfill the objectives of secession and the formation of an independent state in South Sudan.