The Doors of the Chapel and the Keys to the Palace of Louis IX considers two virtually unknown sculpted portals located in the second bay on the north side of the Sainte-Chapelle, the monumental reliquary chapel built by Louis IX in the royal palace of Paris between 1239 and 1248. Examining archaeological and archival documentation concerning these portals, Meredith Cohen provides important new insights about the initial design and function of the Sainte-Chapelle, its attendant structures, and the royal palace. After charting the history of the Chevesserie, the building to which the portals issued, Cohen proposes a relative chronology for the other structures in the palace attributed to Louis IX, arguing that construction of the Sainte-Chapelle generated major changes, which defined the palace as symbol of the royal state starting in the thirteenth century. This article contributes to the research in medieval architecture that views great monuments as part of highly complex historical topographies.