Following the death of St. Louis, a new court fashion of ostentatious display was introduced into French stained glass with the advent of Queen Marie de Brabant, who in 1274 became the second wife of St. Louis's heir Philippe le hardi. Little stained glass in this new style survives, since the very motifs that made it different -- large donor 'portraits, ' elaborate heraldry, lavish name-inscriptions -- were targets of vandalism. This study reconstructs two ensembles in the new style, at Mussy-sur-Seine in southern Champagne & at the medieval hospital of Tonnerre in Burgundy. Both can be connected with the extraordinary figure of Marguerite de Bourgogne. Titled the Queen of Sicily, she was a revered agent of Christian charity of the Gothic era. 50+ illustrations.