Current scholarship on medieval stained-glass windows has allowed us to appreciate more fully how they were engaged in the devotional life of the buildings they illuminate. But rose windows, which are the very large circular apertures on the terminal arms of Gothic structures, have not been included in these analyses. The conservation currently taking place at Chartres Cathedral allows us to consider rose windows with new eyes, and grasp their materiality, legibility for their medieval beholders, and meaning within the larger glazing cycle.