A majestic light and an open space towards the sky to take the faithful out of the dark darkness of the Romanesque. Gothic architecture was an artistic revolution. Not only because of its pointed arches, its flying buttresses or its ligature vaults. These were new times, there was a different way of thinking and it was especially reflected in its religious buildings.
These tall stone structures began to bear fruit around the year 1100 and were combined with large expanses of glass, pointed spires, stylized columns, or huge arches. All well mixed to guarantee the luminosity of the spaces.
Although in the Renaissance they tried to despise this style by calling it "Gothic", that is, "barbaric" (the art of the Goths), the truth is that the movement that began with the reform of the Cathedral of Saint Denis brought innovations that still amaze today. The last of them has been discovered thanks to a misfortune. Every cloud has a silver lining.
When the fire swept through Notre-Dame in 2019 it significantly damaged the structure of the building. But, in turn, it allowed different investigations to be carried out that have led experts from the University of Paris to discover that this was the first Gothic cathedral that was built using iron to join the stones.
Once the works were finished in the middle of the 12th century, Notre-Dame was the tallest construction ever erected, reaching up to 32 meters. Previous research suggests that this record was made possible by a combination of a number of architectural innovations, including the use of iron, an element common in more recent cathedrals.
The 2019 fire and subsequent restoration have allowed archaeologist Maxime L'Héritier and his colleagues to access previously hidden parts of the building that contained clues to the possible use of iron in its construction. The specialists obtained samples of, for example, 12 staples used to join stones in different parts of the building, including the stands, the corridors of the nave and the upper walls.
The researchers applied radiocarbon dating systems, as well as microscopic, chemical, and architectural analysis to better understand these basic architectural elements. Analysis suggests that staples were in fact used as early as the early construction phases, in the 1160s, making it the first such building to employ this revolutionary technique.
“Radiocarbon dating reveals that Notre-Dame de Paris is inarguably the first Gothic cathedral where iron was thought of as a real building material to create a new form of architecture. Medieval builders used several thousand iron staples throughout its construction”, state the authors of the article published in the PLOS ONE magazine.
Combined with other archaeological and historical insights for that time period, the analyzes also provide information that could help deepen our understanding of iron trade, circulation, and forging in 12th- and 13th-century Paris. For example, many of the cleats appear to have been forged by welding together pieces of iron obtained from different sources of supply.
The researchers note that further analysis of the Notre-Dame samples and a more comprehensive database of historical iron producers in the region are needed to confirm and expand their new findings on the medieval Parisian iron market.
