The X-Group Culture was an ancient civilization that existed from ca. 300 CE to ca. 600 CE. It was centered in Nubia stretching from the Dodekaschoinos in the north to Delgo in the south. George A. Reisner, who first discovered their civilization, used the term X-Group Culture for lack of a more exact historical definition.
- W.B. Emery, Nubian Treasure: An Account of the Discoveries at Ballana and Qustul, London 1948. pl. 13A
- G. Mokhtar, General History of Africa II. Ancient Civilizations of Africa, 1981, ISBN 0435948059,p.326.
- Bruce Trigger, History and Settlement in Lower Nubia. New Haven: Yale University Publications in Anthropology, 1965.