GLASS

Glass emerged in the origins of civilization, in Egypt and Mesopotamia; however, the use of glass in architecture had to wait a long time. Windows were unknown in these two states and also in Greece and Rome. Important buildings such as the Parthenon in Athens or the Cemetery in Rome had to illuminate their interiors with an opening in the roof, which meant that not just sun, but also rain would go in. The first windows were closed with wooden panels or with blinds or shutters, which completely darkened them. Even a relatively short time ago, traditional architecture in Japan only used fixed or moving partitions, called fusuma, closed with karakami paper. For centuries, in many countries, the common solution to closing windows without losing all of the light was to use waxed paper or cloth and parchments.
Towards the end of the Roman Empire, the most important buildings put small pieces of glass which could be joined by lead canes on the windows. The Late Middle Ages did not excel in technical progress and the buildings only used small openings for lighting purposes.
However, starting in 1000 A.D., Europe experienced an enormous social advancement with the reappearance of the cities. Great buildings like cathedrals surpassed ancient construction techniques, increasing their height - in search of greatness – without increasing mass, which allowed them to increase the size of windows. In some countries like France, stained-glass windows reached their peak in the 12th century in the cathedral of Chartres.