Fatimid Rock Crystal Sculpture of a Bird - OF.074, Origin: Egypt, Circa: 1000 AD to 1100 AD, Dimensions:3.1" (7.9cm) high x 2.65" (6.7cm) wide, Collection: Islamic Art, Style: Fatimid, Medium: Rock Crystal, At the height of their power, the Fatimid Caliphate ruled much of the Islamic world, including North Africa, the Hejaz, and the Eastern Mediterranean, from their capital in Cairo. However, their roots can be traced to the shores of Ifriqiya in modern day Tunisia and eastern Algeria where in 909 A.D. an imam from the Ismaili sect of the Shia branch of Islam declared himself caliph and adopted the name of al-Mahdi (the Divinely Guided One). Directly opposing the power of the Sunni Abbasids, the Fatimids legitimized their claim to authority by tracing their descent to Muhammad by way of his daughter Fatima (hence the name Fatimid) and her husband Ali, the first Shia imam. Soon after their founding, the Fatimids began to expand outwards, swiftly bringing all of the Maghreb under their dominion. Thereafter, the Fatimids set their sights to the East where the Abbasids centers of power lay.