Abdullah Ibn-Mohammed or Abdullah al-Taashi or Abdullah al-Taaisha, also known as "The Khalifa" (Arabic: c. عبدالله بن سيد محمد خليفة; 1846 – November 25, 1899) was a Sudanese Ansar General and ruler who was one of the principal followers of Muhammad Ahmad. Ahmad claimed to be the Mahdi, building up a large following. After his death Abdallahi ibn Muhammad took over the movement, adpoting the title of Khalifat al-Mahdi (usually rendered as "Khalifa"). His attempt to create an Islamist military dictatorship led to widespread discontent, and his eventual defeat and death at the hands of the British.
Abdullah was born into the Ta'aisha Baqqara tribe in Darfur around 1846 and was trained and educated as a preacher and holy man. He became a follower ofMohammed Ahmed "the Mahdi" around 1880 and was named Khalifa by the Mahdi in 1881, becoming one of his chief lieutenants. The other Kalifas were Ali wad Hilu and Muhammad Sharif. He was given command of a large part of the Mahdist army, and during the next four years led them in a series of victories over the Anglo-Egyptians. He fought at the Battle of El Obeid, where William Hicks's Anglo-Egyptian army was destroyed (November 5, 1883), and was one of the principal commanders at the siege of Khartoum, (February 1884 - January 26, 1885).
After the unexpected death of the Mahdi in June 1885, Abdullah succeeded as leader of the Mahdists, declaring himself "Khalifat al-Mahdi", or successor of the Mahdi. He faced internal disputes over his leadership with the Ashraf and he had to suppress several revolts in 1885-1886, 1888-1889, and 1891 before emerging as sole leader. At first the Mahdiyah was run on military lines as a jihad state, with the courts enforcing Sharia law and the precepts of the Mahdi, which had equal force. Later the Khalifa established a more traditional administration.
He felt the best course of action to keep the internal problems at a minimum was to expand into Ethiopia and Egypt. The Khalifa invaded Ethiopia with 60,000 Ansar troops and sacked Gondar in 1887. He later refused to make peace. He successfully repulsed the Ethiopians at the Battle of Metemma on March 9, 1889, where the Ethiopian emperor Yohannes IV was killed. He created workshops to maintain steam boats on the Nile and to manufacture ammunition. He underestimated the strength of the Anglo-Egyptian forces and suffered a crushing defeat in Egypt.
The Egyptians failed to counter up the Nile; however in the 1890s his state became strained economically, and suffered from crop failures instead. The Ashraf, in November 1891, decided to press again, but were put down one final time and they were prevented from causing any further issues. During the next four years, he strengthened the military and financial situation of the Sudan; however this was not enough as, the Sudan became threatened by Italian, French and British imperial forces which surrounded it. In 1896, an Anglo-Egyptian army under General Herbert Kitchener began the reconquest of the Sudan.
Defeat and death
Following the loss of Dongola in September 1896, then Berber and Abu Hamed to Kitchener's army in 1897, the Khalifa Abdullah sent an army that was defeated at theBattle of Atbara River on April 8, 1898, afterwards falling back to his new capital of Omdurman.
At the Battle of Omdurman on September 2, 1898 his army of 52,000 men was destroyed. The Khalifa then fled south and went into hiding with a few followers but was finally caught and killed by Sir Reginald Wingate's Egyptian column at Umm Diwaikarat in Kordofan on November 24, 1899.
Devout, intelligent, and an able general and administrator, the Khalifa was unable to overcome tribal dissension to unify Sudan, and was forced to employ Egyptians to provide the trained administrators and technicians he needed to maintain his self-proclaimed Islamist military dictatorship.