This dissertation studies the imagery of armor and its materiality in medieval romance, and in so doing maps the early history of one of our culture’s most powerful and sustaining cultural conceits. In medieval romance, armor is used to structure narrative; it is used to create formal aesthetic effects; it is even used as a kind of literary character, outperforming––outshining––even the beautiful maiden as the focus of the knightly quest. While scholars have studied medieval armor from a variety of perspectives, notably its metallurgy and as a manifestation of gendered identity, armor’s effectiveness as a literary apparatus has yet to receive a thorough treatment. This project attempts to mediate two heretofore-unconnected critical conversations. The first concerns established theories of gender and fashion that have already thoroughly explored the role of clothing and fashion in crafting identity. I relate these treatments of the performative and material identity of medieval chivalry to the specific material realities of knighthood. This approach incorporates historical and archaeological studies of medieval metallurgy into literary readings influenced by Thing Theory. The overabundance of armor in medieval narrative, I argue, articulates the medieval knight as an assemblage, an object that attains its most significant meaning only when it has been combined with all of the elements that make it whole. This wholeness, moreover, is, only temporary since the violent labor of knightly combat often leads to the destruction, disintegration, or disassemblage of the chivalric body and its armor. The fact that this state of dissassemblage can be repaired, rescripted and repeated presents a fascinating material modularity to medieval chivalric identity. My work also participates in a vein of materialist studies seeking to bridge a gap between a new critical interest in manuscript materiality and established scholarship in early modern material culture.