This dissertation examines the patronage of Marie de Brabant, queen of France (1260-1322), and how her commissions transformed the atmosphere of the late Capetian court. Bringing with her from her native duchy of Brabant an established set of cultural preferences strikingly different from those that the saintly Louis IX had promoted in Paris for the previous half century, she introduced a love of secular material and elaborate ceremony upon her arrival in 1274. Taking the form of manuscript illumination, sculpture, stained glass, and architecture, as well as literature, music, science, history, genealogy, ritual, and finery, Marie’s patronage set a trend for courtly consumption for the remainder of the medieval period. Nearly always political in nature, her commissions were nonetheless sumptuous to behold, whether secular or sacred in content and they announced her status as Carolingian princess and French queen. Analysis of the frontispiece of Bibliothèque de l’Arsenal Ms. 3142, a richly illuminated miscellany of fictional, historical, and didactic poetry is crucial for understanding Marie’s taste and priorities, and is complemented by study of her other commissions in Brabant and France. These commissions varied from large scale -- such as the addition of chapels to the east end of the church of Notre-Dame in Mantes or window programs for the chapel of St. Nicholas at the church of St.-Nicaise in Reims and her parent’s necropolis at the church of the Dominicans in Louvain -- to smaller format -- the châsse of Ste. Gertrude at Nivelles or the donor statues of the chapelle de Navarre at Mantes. Most numerous, however, are the manuscripts that made up her diverse library which included the secular romances of Adenet le Roi and the scientific treatises of Guillaume de Nangis as well as historical and religious texts all of which were illuminated by the most renowned and creative artists of the day. After an analysis of her patronage as queen and widow, I look to how her activities as patron and collector influenced other late Capetian royal women, many of whom Marie had raised and whose activities, in turn, complemented and complicated their mentor’s vision of queenship. / text