Unknown Artist
The extent of the damage is not yet known. Luckily, it's now known that the north rose window created ca. 1250-1260 and consisted of 18 lancet windows survived. Most of the original 13th century glasswork was until yesterday still intact, filtering light into a rainbow of blues, reds, greens, browns and yellows. The technology behind creating such stained glass was very complex. Colored glass was cut to size by heating or with a diamond. Details (facial features, drapery, foliage, etc.) were painted on with a mixture of cullet (scrap glass), copper and Greek sapphire dissolved in wine or urine. This 'glass painting' was baked again, stimulating further chemical reactions that yielded visually striking results. In the center oculus of the north rose window was an image of the enthroned Virgin Mary holding the Christ Child. Surrounding them were images of kings and prophets from the Old Testament.
Hopefully one day it can be restored to its former glory.
Zuzanna & the DailyArt Team.
P.S. Alexandra wrote a short passage about the cathedral in DailyArt Magazine and you can read it here.