Abstract Saint Louis, or King Louis IX of France, served as a legitimizing figure for French royal dynasties during the centuries after his death in 1270. The idea of a holy lineage or beata stirps, in which sanctity was transmitted through blood instead of being solely an attribute of the kingly office, was well established in Europe by the end of the thirteenth century. Louis’s descendents, both the monarchs themselves and others in the royal line, thus utilized his figure to validate their own claims to hereditary sanctity. In the late fifteenth century, within this dynastic context, an elaborately illuminated manuscript devoted to Saint Louis, Le livre des faiz monseigneur Saint Loys (BnF MS fr. 2829), was produced for the Bourbon family. The text of Le livre des faiz merges the historical and hagiographical traditions about Saint Louis. The manuscript includes both a life of Louis and a collection of miracle accounts, but the passages in the life, although drawn from both traditions, are arranged roughly chronologically. This new textual context and the lavish size and quantity of the illuminations in the manuscript provide an opportunity for the creation of new iconography. Among the many innovative features of the visual program is an emphasis on Louis’s family, including the women of his lineage in both directions—his mother, his sister, and his daughters. The images of these female family members highlight their own pious behavior and place them in a context of sanctity and dynasty, thus visually supporting the idea of the beata stirps for a late-fifteenth-century audience.