The biography of the Prophet Mummad (sira) of the fourteenth-century Ottoman scholar Mustafa Darir stands as the most widely read biography of Muhammad in the Ottoman Empire. The Ottoman sultan Murad III (r. 1574-95) commissioned an illustrated version of this work in the late sixteenth century. With its more than 800 miniatures, the resulting illuminated manuscript is rightly considered the quintessence of Ottoman miniature art. However, not much is known about the text of this work. Darir’s sira was a re-rendering of the sira of the mysterious thirteenth-century scholar Abu Hasan al-Bakri, who was known to have Shiite sympathies. Indeed, a close reading of Darir’s work reveals a reverence for Ali almost equal to that shown for Muhammad. Why and how did the Ottoman sultan, a supposed champion of Sunnism, come to commission a work with marked Shiite sympathies, and why and how did it become so popular? In an effort to answer these questions, this paper examines the text of Darir’s sira to highlight its Alid features. In addition, I discuss the wider phenomenon of reverence for Ali and other members of the Prophet’s family – what I call ahl al-baytism –in the Ottoman intellectual world of the sixteenth century. I argue that Ottoman spiritual attitudes were characterized far more by confessional ambiguity and ahl-al-baytism than by rigid confessional boundaries.