Abdullah ibn-Mohammed al-Khalifa or Abdullah al-Khalifa or Abdallahi al-Khalifa, also known as "The Khalifa" 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. 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.

Sudan, officially the Republic of the Sudan, is a country in Northeast Africa. It borders the Central African Republic to the southwest, Chad to the west, Egypt to the north, Eritrea to the northeast, Ethiopia to the southeast, Libya to the northwest, South Sudan to the south, and the Red Sea. It has a population of 45.7 million people as of 2022 and occupies 1,886,068 square kilometres, making it Africa's third-largest country by area and the third-largest by area in the Arab League. It was the largest country by area in Africa and the Arab League until the secession of South Sudan in 2011; since then both titles have been held by Algeria. Its capital and most populous city is Khartoum.