The monumental stained-glass windows in the medieval churches not just conveyed artistic and religious content and values. They can also be considered fields of social communication in which various social groups articulated their specific interests. The lecture will not try to reconstruct the history of stained glass in the Middle Ages in all its stylistic and iconographic ramifications and its entire temporal and geographical extent, but will focus on significant examples that show the basic lines of social discourse and the forms and symbols of social communication in the Middle Ages.