This thesis explores the evolution of stained glass windows throughout the various Gothic periods in Gothic cathedrals, focusing on Chartres Cathedral, Reims Cathedral, Bourges Cathedral, and Sint-Janskerk in Gouda. The research investigates developments in stained glass techniques, designs, and symbolism, and elaborates on the educational purpose and the link between architectural innovations and the windows. How these innovations enabled larger and more detailed stained glass windows. It also considers how perceptions and uses of stained glass shifted over time, from purely religious functions to more diverse artistic expression. And the importance of preserving the historical and social value of these windows.

By combining historical, visual, material, and comparative analyses, this research provides a comprehensive understanding of Gothic stained glass windows. It contributes to existing literature by focusing specifically on the value of these windows, in well-known cathedrals, rather than treating it as a minor aspect of Gothic architecture. The findings demonstrate how stained glass windows reflect broad changes throughout the Gothic period and beyond. This research enhances the appreciation for this art form and its everlasting historical significance.