I’ve written about Art Nouveau-era stained glass from Tiffany & Co. and I’ve written about how stained glass was a key aspect of Gothic architecture. But I’ve never actually written specifically about Gothic-era stained glass … the renowned rose windows of Gothic cathedrals.
Circular windows date back — like a surprising number of architectural fascinations — to the Roman period. The oculus at the top of the Pantheon in Rome is both an engineering feat and an opening to allow natural light in, although it has the slight side effect of also allowing any other weather into the dome as it is uncovered. (Though some suggest rain is a highlight of the design…) While two and two weren’t put together to create stained glass windows in this era as far as we have evidence, glass was used for artwork in Roman buildings as tiles in mosaics.
The first textual references to stained glass in framed windows are from the 2nd or 3rd centuries CE, they were much more common in churches throughout Europe by the 7th century. At this point, they were often copying illuminated manuscripts. Abbot Suger, whom my autocorrect wants to call Abbot Sugar, is commonly recognized as the first to bring stained glass windows into an art form in their own right. His work on remodeling the Basilique Royale de Saint-Denis is regarded as the first fully Gothic work — detailed about over here. Suger instigated a rich blue color as the background for the stained glass artworks in Saint-Denis, rather than the prior common backing of white or clear — adding a whole new level of color to the art.
The color gained both acclaim and derision, as certain sects of Christianity believed in stricter rules of embellishments for churches and monasteries — which is why some locations bear a Gothic flair but in a more monochrome patina created with silver stain or vitreous paint on the surface of the glass, a treatment called grisailles.
“Stained glass” technically encompasses two different approaches to glass artwork. The first is colored glass: sand and potash mixed with a metal oxide powder at extremely hot temperatures to create pigmented glass. Copper oxide would create shades between green to blue, while cobalt would be used for a deep blue (mostly likely the source of the backgrounds in Saint-Denis), purple came from manganese, and yellow from antimony, and then gold for violet through deep red. Whether the glass itself was colored or clear, the next steps are the same.
The molten glass would be blown and flattened into sheets (air bubbles in older glass anyone?), once dried the glass would be cracked into the general shape it needed to be in and then slowly and carefully refined. This is the point where the second approach of a paint layer on top of the glass comes into play; whether it was colored paint, as a cheaper approach to colored blown glass, or an artistic choice, like grisailles, or used to add highlights to the design.
Once the glass was in its final form, it would be joined together with cames, lead strips in H-shapes that sat around the edges of the glass, welded together to form panels. A bit of putty in and around the glass and cames for waterproofing, then the panels would be compiled into an iron armature or frame to form the finished window.
As masonry improved and Gothic architecture became stylistically more complex, masonry supports called tracery within the window space started improving how large the windows could be. The classic and largest demonstration of this is the North Rose Window in Notre-Dame de Paris at 12.9 meters across (that’s about 42.3 ft if you’re like me and get brain-fog when it comes to metric). This window is actually in the running for the largest window globally … not just for a rose window, window-at-all. It was constructed in 1220 and still retains most of its original tracery and glass — even surviving the blaze that de-roofed Notre Dame just over two years ago.
Now, to be fair to the Gothic style, it has to be acknowledged that there were two common types of windows, not just rose: rose and lancet. The rose windows are the more awe-inspiring for the wide sizes they were pushed to, but lancet windows have their places as well, some of them particularly tall. One such highlight is Saint-Chapelle — also on the Île de la Cité in Paris, two blocks from Notre-Dame — where the lancet windows are 15.4 meters tall (over 50 ft).
The French Gothic most prominently features rose windows, with a few found in cathedrals in Italy of the same era. By the end of the Gothic period, Chartres, Reims, Amiens, Strasburg, and of course Paris cathedrals all featured at least one rose window. During the Gothic Revival era, the style spread globally, and rose windows featuring stained glass can now be found from Australia to Ecuador to the US and across Europe.
Of course, it’s not quite that simple realistically … buildings built in the original Gothic era have all undergone some form of remodeling and upkeep to remain standing — oftentimes, that has included the glass arts. Westminster Abbey is an excellent case study. Stained glass windows were originally added to the building when it was rebuilt in the Gothic era in the 13th century — today the six surviving complete panels from that era reside in the Queen’s Diamond Jubilee Galleries because we don’t know where they originally were situated within the abbey grounds. Beyond those six, around 30,000 glass fragments dated to between 1246 and 1520 were discovered in a recent remodel project; some of them were then utilized in a new stained-glass piece. Much of the Tudor-era glass from the abbey was lost in WWII, but here and there a few remain. The west window in the abbey nave dates from the 1700s, although it was altered in the late 19th century. In 1902, the south rose window received its most recent glass replacement after glass from the previous century had darkened. A few decades later, many stained-glass pieces lost during the Blitz were replaced, with some of the surviving fragments of original glass being repurposed into stained glass chandeliers. The most recent addition was in September 2018, a Yorkshire country scene celebrating Queen Elizabeth II’s reign added to the north transept.
Today, Gothic stained glass and Gothic-inspired stained glass rest side-by-side in buildings globally, making visiting each building a beautifully-illuminated walk through eight hundred years of artistry.