Stained-glass windows adorn many churches. Although the art of making colored (or “stained”) glass had existed for millennia, originating in ancient Egypt, it reached a new level of sophistication in medieval Europe. As the demand for stained-glass windows to decorate churches increased, artisans experimented with techniques to produce glass with more colors and fewer impurities. The cathedral in Augsburg, Germany, has some of the earliest stained-glass windows. Still intact and functional, five windows in the cathedral’s south clerestory date to the late 11th or early 12th century. Each features a prophet from the Old Testament: Moses, David, Jonah, Hosea, […]