A surviving member of the Abbasid House was installed as Caliph at Cairo under the patronage of the Mamluk Sultanate three years later ; however , the authority of this line of Caliphs was confined to ceremonial and religious matters , and later Muslim historians referred to it as a `` shadow '' Caliphate . A surviving member of the Abbasid house was installed as caliph at Cairo under the patronage of the newly formed Mamluk Sultanate three years later ; however , this line of caliphs had generally little authority although some Abbasid rulers had the actual rule over the Mamluk Sultans . Later Muslim historians referred to it as a `` shadow '' caliphate .