Sudan's population collapse during the Mahdist period is well attested, but it combines the war's own combat deaths, the Mahdist state's internal campaigns against rival Sudanese groups, the 1888 to 1892 famine, and the disease that followed it, and no modern historian has disaggregated a war caused figure from the rest.
What would resolve this A modern demographic or historical study working through Sudanese provincial and Mahdist state records to separate combat and internal campaign deaths from the famine and disease mortality of the same years.
OpenSudanese history; historical demographyP. M. Holt, The Mahdist State in the Sudan, 1881-1898: A Study of Its Origins, Development and Overthrow