Writer and science teacher Andy Connelly finds inspiration in the stained glass of medieval cathedral. He discusses the science of stained glass in an article for The Guardian.
Sheets of glass both blown and cast have been used architecturally since Roman times. Writers as early as the fifth century mention coloured glass in windows. Around AD 1000 Europe became less war-like, and church building and stained glass production began to flourish. However, these churches were Romanesque in style with massive walls and pillars to bear their weight and so had only relatively small windows.
But by the 12th century the pointed arch and flying buttresses of the Gothic style were allowing builders to insert "walls of light", giant windows that filled the church interior with the perfect light of God.