Early History of the Region :
Sudan was a collection of small, independent kingdoms and principalities from the beginning of the Christian era until 1820-21, when Egypt conquered and unified the northern portion of the country. However, neither the Egyptian nor the Mahdist state (1883-1898) had any effective control of the southern region outside of a few garrisons. Southern Sudan remained an area of fragmented tribes, subject to frequent attacks by slave raiders.
The Mahdis Crusade:
In 1881, a religious leader named Muhammad ibn Abdalla proclaimed himself the Mahdi, or the expected one, and began a religious crusade to unify the tribes in western and central Sudan. His followers took on the name Ansars (the followers) which they continue to use today and are associated with the single largest political grouping, the Umma Party, led by a descendant of the Mahdi, Sadiq al Mahdi.
Anglo-Egyptian Response:
Taking advantage of dissatisfaction resulting from Ottoman-Egyptian exploitation and maladministration, the Mahdi led a nationalist revolt culminating in the fall of Khartoum in 1885. The Mahdi died shortly thereafter, but his state survived until overwhelmed by an invading Anglo-Egyptian force under Lord Kitchener in 1898. While nominally administered jointly by Egypt and Britain, Britain exercised control, formulated policies, and supplied most of the top administrators.
Sudan Gains Independence:
In February 1953, the United Kingdom and Egypt concluded an agreement providing for Sudanese self-government and self-determination. The transitional period toward independence began with the inauguration of the first parliament in 1954. With the consent of the British and Egyptian Governments, Sudan achieved independence on January 1, 1956, under a provisional constitution.
The new constitution was silent on two crucial issues for southern leaders - the secular or Islamic character of the state and its federal or unitary structure. However, the Arab-led Khartoum government reneged on promises to southerners to
