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.
Ansar (Sudan)
Muhammed Ahmad died a few months later. His successor, Abdallahi ibn Muhammad, maintained the independence of the Mahdist state until 1898, when an Anglo-Egyptian force regained control. The Mahdi's eldest surviving son, Abd al-Rahman al-Mahdi, was the religious and political leader of the Ansar throughout most of the colonial era of the Anglo-Egyptian Sudan (1898-1955) and for a few years after the Sudan gained independence in January 1956. His descendants have led the movement since then.