Wedged between the better known reigns of the Fatimid Imam-caliph, al-Mu?izz li-D?n All?h (r. 341-365/953-975), termed the Founder of Cairo, and that of al-??kim bi-Amr All?h (r. 386-411/996-1021), called the Caliph of Cairo, there is the often eclipsed twenty-one-year reign of the fifth Fatimid Imam-caliph, al-?Az?z bi?ll?h, the first to begin his rule in Egypt As the third of four sons, al-?Az?z had been among the father’s retinue that took up residence in Cairo two and half years prior to his accession. Late in this period al-?Az?z’s elder brother, the wal? al-?a?d and heir-apparent ?Abd All?h, suddenly died, leading to the appointment of al-?Az?z himself days only before al-Mu?izz’s own death in 365/975. Thrust thus swiftly into state prominence, al-?Az?z thereafter embarked upon a plan to lay the foundations of lasting Fatimid rule in Egypt. However descriptions of al-?Az?z in the primary sources, often mirrored in secondary literature, present him as a figure who was disinclined to rule directly, drawn instead to princely pursuits such as lion-hunting, falconry and the collection of precious gems and rarities. This characterisation resulted in part from the concurrent rise of al-?Az?z’s famous vizier Ya?q?b b. Killis [d. 380/991], the illustrious financial administrator of his age, often posited in secondary literature as the ‘power behind the throne’. Through a close review of the sources, this paper reappraises the reign of al-?Az?z seeing him rather as a sovereign at the helm of affairs, striving to create institutional frameworks to buttress Fatimid rule. Ibn Taghri Birdi (d. 874/1470), an otherwise zealous critic of the Fatimids, noted that al-?Az?z was “was the best of the Fatimid caliphs, notably in comparison to his father, al-Mu?izz and his son, al-??kim.”