Muhammad Ahmad in the context of "Typhus"

Turco-Egyptian Sudan (Arabic: السودان التركي المصري), also known as Turkish Sudan or Turkiyya (Arabic: التركية, at-Turkiyyah), describes the rule of the Eyalet and later Khedivate of Egypt over what is now Sudan and South Sudan. It lasted from 1820, when Muhammad Ali Pasha started his conquest of Sudan, to the fall of Khartoum in 1885 to Muhammad Ahmad, the self-proclaimed Mahdi.

The Mahdist State, also known as Mahdist Sudan or the Sudanese Mahdiyya, was a state based on a religious and political movement launched in 1881 by Muhammad Ahmad (later Muhammad al-Mahdi) against the Khedivate of Egypt, which had ruled Sudan since 1821. After four years of struggle, the Mahdist rebels overthrew the Ottoman-Egyptian administration and established their own "Islamic and national" government with its capital in Omdurman. Thus, from 1885 the Mahdist government maintained sovereignty and control over the Sudanese territories until its existence was terminated by Anglo-Egyptian forces in 1898.

Muhammad Ahmad al-Mahdi enlisted the people of Sudan in what he declared a jihad against the administration that was based in Khartoum, which was dominated by Egyptians and Turks. The Khartoum government initially dismissed the Mahdi's revolution. He defeated two expeditions sent to capture him in the course of a year. The Mahdi's power increased, and his call spread throughout Sudan, with his movement becoming known as the Ansar. During the same period, the 'Urabi revolution broke out in Egypt, with the British occupying the country in 1882. Britain appointed Charles Gordon as General-Governor of Sudan. Months after his arrival in Khartoum and after several battles with the Mahdi rebels, Mahdist forces captured Khartoum, and Gordon was killed in his palace. The Mahdi did not live long after this victory, and his successor Abdallahi ibn Muhammad consolidated the new state, with administrative and judiciary systems based on their interpretation of Islamic law. The Coptic Christians, who composed a substantial portion of the country's population, were forced to convert to Islam.

Sadiq al-Mahdi (Arabic: الصادق المهدي, romanized: aṣ-Ṣādiq al-Mahdī; 25 December 1935 – 26 November 2020), also known as Sadiq as-Siddiq, was a Sudanese political and religious figure who was Prime Minister of Sudan from 1966 to 1967 and again from 1986 to 1989. He was head of the National Umma Party and Imam of the Ansar, a Sufi order that pledges allegiance to Muhammad Ahmad (1844–1885), who claimed to be the Mahdi, the messianic saviour of Islam.

Yohannes IV (Tigrinya: ዮሓንስ ፬ይ Rabaiy Yōḥānnes; horse name Abba Bezbiz also known as Kahśsai; born Lij Kahssai Mercha; 11 July 1837 – 10 March 1889) was Emperor of Ethiopia from 1871 to his death in 1889 at the Battle of Gallabat, and king of Tigray from 1869 to 1871. During his reign he successfully defended Ethiopia against a large-scale Egyptian invasion.

In his earlier years, he rebelled against Tewodros II; having risen to power in the 1860s, he maintained the policy of Tewodros, that of continued unification and also implemented a policy of touring entire regions and meetings with governors. He assisted the British in their British expedition to Abyssinia which ended in Tewodros' suicide, from which Yohannes was rewarded in ammunition and artillery. He regarded Islam as a hindrance to the stability of the state and worked to strengthen Christian dominance in Ethiopia. Its estimated that he had converted 550,000 Oromos and Jebertis to Christianity. In foreign policy, he had disagreements and military conflicts with both Isma'il Pasha of the Khedivate of Egypt and Muhammad Ahmad during the latter's Mahdist War.

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.

The Nuba Mountains (Arabic: جبال النوبة), also referred to as the Nuba Hills, are an area located in South Kordofan, Sudan. The area is home to a group of indigenous ethnic groups known collectively as the Nuba peoples. They are not the same as the Nubians who are indigenous to north Sudan. Rather their name is derived from the name of the mountains, “Nuba”. In Antiquity, the area was a part of the Kingdom of Kush. In the Middle Ages, the Nuba mountains had been part of the Nubian kingdom of Alodia. In the 18th century, they became home to the kingdom of Taqali that controlled the hills of the mountains until their defeat by Mahdi Muhammad Ahmad. After the British defeated the Mahdi army, Taqali was restored as a client state. Infiltration of the Messiria tribe and Muraheleen of Baggara Arabs has been influential in modern conflicts. Up to 1.5 million people live in the mountains, mostly ethnic Nuba, with a small minority of Baggara.

The Ansar (Arabic: أنصار) are a Sufi religious movement in the Sudan whose followers are disciples of Muhammad Ahmad (12 August 1844 – 22 June 1885), a Sudanese religious leader based on Aba Island who proclaimed himself Mahdi on 29 June 1881. His followers won a series of victories against the Egyptians, culminating in the capture of Khartoum in January 1885.

When Muhammed Ahmad died a few months later, his successor, Abdallahi ibn Muhammad, maintained the independence of the Mahdist State until 1898, when an Anglo-Egyptian force re-conquered the area. The Mahdi's eldest surviving son, Abd al-Rahman al-Mahdi, was the religious and political leader of the Ansar throughout most of the colonial era of Anglo-Egyptian Sudan (1898–1955) and for a few years after the Sudan gained independence in January 1956. His descendants have led the movement since then.

The siege of Khartoum (also known as the battle of Khartoum or fall of Khartoum) took place from 13 March 1884 to 26 January 1885. Sudanese Mahdist forces captured the city of Khartoum, Sudan, from its Egyptian garrison, thereby gaining control over the whole of Turco-Egyptian Sudan.

Egypt had conquered Sudan in 1820, but had itself come under British domination in 1882. In 1881, the Mahdist War began in Sudan, led by Muhammad Ahmad who claimed to be the Mahdi. The Egyptian Army was unable to suppress the revolt, being defeated in several battles and retreating to their garrisons. The British refused to send a military force to the area, instead appointing Charles George Gordon as Governor-General of Sudan, with orders to evacuate Khartoum and the other garrisons. Gordon arrived in Khartoum in February 1884, where he found it impossible to reach the other garrisons which were already besieged. Rather than evacuating immediately, Gordon began to fortify the city, which was cut off when the local tribes switched their support to the Mahdi. Approximately 7,000 Egyptian troops and 27,000 (mostly Sudanese) civilians were besieged in Khartoum by 30,000 Mahdist troops, rising to 50,000 by the end of the siege.