Pilgrims visiting Rome in the Jubilee Year 1450 were certain to seek out the wondrous “Image of Pity” (Imago Pietatis). This, they believed, was the original death-portrait (effigies) of Christ made “from life” by Pope Gregory in ancient Christian times. The object of erstwhile pilgrim desire is a Byzantine micromosaic icon of the Man of Sorrows enshrined since ca. 1400 at Santa Croce in Gerusalemme in Rome. My dissertation proceeds from a close study of this icon and its “life” as a cult-object between East and West in the later Middle Ages. Embedded within an extraordinary triptych reliquary and showcased in Santa Croce’s subterranean Jerusalem Chapel, the icon was the centerpiece to a Christological tableau vivant that allegorized Real Presence in the Eucharist and emblematized the Roman Church. My analysis of this spectacle affords insight into newly emergent criteria for what constituted “real” in cult-objects in the Quattrocento, and charts the interdependent functions of an image, its frame, its chapel, and its church in the creation of a New Jerusalem in Rome.