The Ottoman rule of Sudan began in 1821 with the annexation of South Sudan to the Ottoman Empire and ended when Mohammad Ahmad proclaimed himself the Mahdi and led a revolt against Ottoman rulers, forcing them out of Sudan and declaring the establishment of a Mahdist state in 1885. However, the Muslim state failed to survive and was soon recaptured by the Anglo-Egyptian force in 1898. Britain and Egypt signed a condominium agreement under which Sudan was to be administered jointly.

While Britain set out to draw the Sudanese borders in a way that ultimately served its private interests, the nationalist Sudanese forces were starting to harbor deeper hatred and rage against the colonialists. The year 1924 was marked by vehement events. Several demonstrations were staged by the students of the Military Academy in addition to protests led by the White Brigade League, an organized nationalist resistance movement headed by an army officer Ali Abdul Latif. Soon enough, these movements escalated into a military conflict between the British forces and the Sudanese nationalists, culminating in the assassination in Cairo of Sir Lee Stack, Governor - General of Sudan. The British were infuriated by the incident and reacted by expelling all Egyptian officials from Sudan. However, the Sudanese nationalists chose to side with the Egyptians against the British forces and killed dozens of colonialist troops in a heroic confrontation that preceded the killing of chief Sudanese commander Abdul Fadeel Almaz.

In 1930, the British decided to rule the North and South of Sudan under separate administrations. The Egyptians backed up the nationalist movement in the north while the south remained isolated. The compromises of the British forces became clearly evident in 1936 when they established a North Sudan Advisory Council to prepare the North Sudan for self-rule. Later between 1940 and 1945, a political movement known as the Graduates’ Congress emerged and pressured the British administration to help the South Sudan keep up with the education and development reforms occurring in the North.

These pressures resulted in the formation of a 13-member legislature and a council of ministers in 1948, which constituted the first step toward independence. An agreement with the joint rule followed in 1954, granting Sudan the right to decide its own destiny. The first general elections were held that year and resulted in victory for the NUP, and its leader, Ismail al-Aihari who became Sudan’s first Prime Minister.

On December 19, 1955, Parliament voted unanimously that Sudan should become “a fully independent sovereign state”. The Sudanese flag was run up the flagpole at 11:00 am 1st January 1956 and a new Arab state was born. Sudan joined the Arab League on January 19, 1956 and the United Nations on November 12 the same year.