Abdullah ibn-Mohammed al-Khalifa or Abdullah al-Taashi or Abdallah al-Khalifa, also known as "The Khalifa" (; 184625 November 1899) was a Sudanese Ansar ruler who was one of the principal followers of Muhammad Ahmad. Ahmad claimed to be the Mahdi, building up a large following. After Ahmad's death, Abdullah ibn-Mohammed took over the movement, adopting the title of Khalifah al-Mahdi (usually rendered as "Khalifa"). He attempted to create a kingdom, which led to widespread discontent and his eventual defeat and death at the hands of the British and Egyptians.
Personal life
Abdullah was born into the Ta'aisha Baqqara tribe 1846 in Um Dafuq and was trained and educated as a preacher and holy man. His father, Mahommed et Taki, had determined to emigrate to Mecca with his family, but the unsettled state of the region prevented him, and he died in Africa after advising Abdullah, to take refuge on the Nile, and to proceed to Mecca at a favourable opportunity.
On his journey, Abdullah met and became a follower of Muhammad Ahmad "the Mahdi" around 1880