"North Rose Window at Notre Dame Cathedral of Chartres"

Because most worshipers were illiterate, stained glass windows played a didactic role, illustrating stories of the Bible and conveying moral meaning. Iconography played an important role in designing such windows, as the number 12, repeated here, symbolized the unity of the trinity times the number 4 representing mankind. The colors, too, were significant, as blue symbolized the Virgin Mary, whereas red symbolized the suffering and passion of Christ. Many of the church’s 176 windows used predominantly this distinctive shade of blue, named the “bleu de Chartres.” The rose was considered to be a symbol of perfect love as well as the “eye of God,” announcing God’s illuminating presence among men. The light, ever changing, radiated through the depths of the cathedral, creating an inspiring otherworldly effect, while the image reflected the sustaining presence of the Virgin Mary as comforting mother to Catholic worshipers of the era.

The windows of Chartres influenced the development of the Rayonnant style, which emphasized the rose window’s radial effect, exaggerating the petal-like shapes radiating from its center into “rays” of colored glass. The church has remained a continuing presence in the cultural imagination, as seen in filmmaker Orson Welles’ description in his film F for Fake (1973) as “this one anonymous glory of all things, this rich stone forest.” UNESCO described the cathedral as “a museum to stained glass.”