Charles George Gordon (Gordon of Khartoum) in 1885. Tewfik's Egyptian forces and those of the United Kingdom were forced to withdraw from almost all of Sudan, with Abdalla subsequently establishing a theocratic state. Abdalla's religious government imposed traditional Islamic laws upon Sudan, and stressed the need to continue the armed struggle until the British had been completely expelled from the country, and all of Egypt and Sudan had been Incorporated under his Mahdiya. Though he died six months after the fall of Khartoum, Abdalla's call was fully echoed by his successor, Abdallahi ibn Muhammad, who invaded Ethiopia in 1887, and penetrated as far as Gondar, and the remainder of northern Sudan and Egypt in 1889. This invasion was halted by Tewfik's forces, and was followed later by withdrawal from Ethiopia. Abdullahi wrecked virtually all of the previous Egyptian, and Fung administrative systems, and gravely weakened Sudanese tribal unities. From 1885 to 1898, I the population of Sudan collapsed from eight to three million due to war, famine, disease and persecution. History After a series of Mahdist defeats, Tewfik's son and successor, Abbas II, and the British decided to re-establish control over Sudan. Leading a joint Egyptian-British force, Kitchener led military campaigns from 1896 to 1898. Kitchener's campaigns culminated in the Battle of Atbara, Andy the Battle of Omdurman. Exercising the leverage which their military superiority provided, the British forced Abbas to accept British control in Sudan. Whereas British influence in Egypt was officially advisory (though in reality it was far more direct), the British insisted that their role in Sudan be formalised. Thus, an agreement was reached in 1899 establishing Anglo-Egyptian rule (a condominium), under which Sudan was to be administered by a governor-general appointed by Egypt with British consent. In reality, much to the revulsion of Egyptian and Sudanese nationalists, Sudan was effectively administered as a British imperial possession. Pursuing a policy of divide and rule, the British were keen to reverse the process, started under Muhammad Ali, of uniting the Nile Valley under Egyptian leadership, and sought to frustrate all efforts to further unite the two countries. During World War I, the British invaded and incorporated Darfur into the Anglo-Egyptian Sudan in 1916. This policy was internalised within Sudan itself, with the British determined to exacerbate differences and frictions between Sudan's numerous different ethnic groups. From 1924 onwards, the British essentially divided Sudan into two separate territories–a predominantly