Siege of Khartoum in the context of "Mahdist State"

The Mahdist War (Arabic: الثورة المهدية, romanized: ath-Thawra al-Mahdiyya; 1881–1899) was fought between the Mahdist Sudanese, led by Muhammad Ahmad bin Abdullah, who had proclaimed himself the "Mahdi" of Islam (the "Guided One"), and the forces of the Khedivate of Egypt, initially, and later the forces of Britain. After four years, the Mahdist rebels overthrew the Ottoman-Egyptian administration with the fall of Khartoum and gained control over Sudan. The Mahdist State launched several unsuccessful invasions of their neighbours, expanding the scale of the conflict to also include the Italian Empire, the Congo Free State and the Ethiopian Empire. They also faced significant internal rebellion.

Anglo-Egyptian forces reconquered Sudan in 1898 and the Mahdist state collapsed following defeat at the battle of Omdurman. The last organised resistance from the Mahdists ended the next year, leading to the creation of Anglo-Egyptian Sudan (1899–1956), a de jure condominium of the British Empire and the Kingdom of Egypt, in which Britain had de facto control over Sudan.

Muhammad Ahmad bin Abdullah bin Fahal (Arabic: محمد أحمد بن عبد الله بن فحل; 12 August 1843 – 21 June 1885) was a Sudanese religious and political leader. In 1881, he claimed to be the Mahdi and led a war against Egyptian rule in Sudan, which culminated in a remarkable victory over them in the Siege of Khartoum. He created a vast Islamic state extending from the Red Sea to Central Africa and founded a movement that remained influential in Sudan a century later.

From his announcement of the Mahdist State in June 1881 until its end in 1899, the Mahdi's supporters, the Ansar, established many of its theological and political doctrines. After Muhammad Ahmad's unexpected death from typhus on 22 June 1885, his chief deputy, Abdallahi ibn Muhammad took over the administration of the nascent Mahdist State.

The Battle of Omdurman, also known as the Battle of Karary, was fought during the Anglo-Egyptian conquest of Sudan between a British–Egyptian expeditionary force commanded by British Commander-in-Chief (sirdar) major general Horatio Herbert Kitchener and a Sudanese army of the Mahdist State, led by Abdallahi ibn Muhammad (the Khalifa), the successor to the self-proclaimed Mahdi, Muhammad Ahmad. The battle took place on 2 September 1898, at Kerreri, 11 kilometres (6.8 mi) north of Omdurman.

Following the establishment of the Mahdist State in Sudan, and the subsequent threat to the regional status quo and to British-occupied Egypt, the British government decided to send an expeditionary force with the task of overthrowing the Khalifa. The commander of the force, Sir Herbert Kitchener, was also seeking revenge for the death of General Gordon, who had been killed when a Mahdist army captured Khartoum thirteen years earlier. On the morning of 2 September, some 35,000–50,000 Sudanese tribesmen under Abdullah attacked the British lines in a disastrous series of charges; later that morning the 21st Lancers charged and defeated another force that appeared on the British right flank. Among those present was 23-year-old soldier and reporter Winston Churchill as well as a young Captain Douglas Haig.