The Mahdist State, also known as Mahdist Sudan or the Sudanese Mahdiyya, is a religious and political movement launched in 1881 by Muammad Ahmad bin Abdullah (later Muhammad al-Mahdi) against the Khedivate of Egypt, which has ruled the Sudan since 1821.

After four years of struggle, the Mahdist rebels overthrow the Ottoman-Egyptian administration and establish their own "Islamic and national" government with its capital in Omdurman.

Thus, from 1885 the Mahdist government maintains sovereignty and control over the Sudanese territories until its existence is terminated by the Anglo-Egyptian forces in 1898.

Mohammed Ahmed al-Mahdi enlists the people of Sudan in what he declares a jihad against the administration that is based in Khartoum, which is dominated by Egyptians and Turks.

The Khartoum government initially dismisses the Mahdi's revolution; he defeats two expeditions sent to capture him in the course of a year.

The Mahdi's power increases, and his call spreads throughout the Sudan, with his movement becoming known as the Ansar.

During the same period, the 'Urabi revolution breaks out in Egypt, with the British occupying the country in 1882.

Britain appoints Charles Gordon as General-Governor of Sudan.

Months after his arrival in Khartoum and after several battles with the Mahdi rebels, Mahdist forces capture Khartoum, and Gordon is killed in his palace.

The Mahdi does not live long after this victory, and his successor Abdallahi ibn Muhammad consolidates the new state, with administrative and judiciary systems based in Islamic law.

Sudan's economy is destroyed during the Mahdist War and famine; war and disease reduce the population by half.

The British reconquered the Sudan in 1898, ruling it after that in theory as a condominium with Egypt but in practice as a colony.