In the late fourteenth-century Processional (London, British Library, MS Add. 57534) made for St. Giles’s Hospital, Norwich, nine brightly colored paintings describe a series of liturgical processions in exceptional detail. The manuscript’s images are, however, most remarkable for what they do not render visible: the human figures who enacted each ritual performance. In the Processional’s paintings the beholder is instead offered a vision of liturgy as an assembly of vasa sacra and ornamenta, invested with considerable authority, even agency, by the artist’s brush. This essay examines how the paintings in the St. Giles’s Hospital Processional represent sacred objects not as the “props” of Christian ritual but as the subject of ritual and the subjects of ritual action. Attending to the imbrication of objecthood and subjecthood in the Processional’s text and images, the essay elucidates the Processional’s participation in a powerful medieval tradition of imitatio rerum: the refashioning of subjectivity after the model of things.