Basilica of Saint Denis in the context of "Sens Cathedral"

Eugène Emmanuel Viollet-le-Duc (French: [øʒɛn vjɔlɛ lə dyk]; 27 January 1814 – 17 September 1879) was a French architect and author, famous for his restoration of the most prominent medieval landmarks in France. His major restoration projects included Notre-Dame de Paris, the Basilica of Saint Denis, Mont Saint-Michel, Sainte-Chapelle, the medieval walls of the city of Carcassonne, and Château de Roquetaillade in the Bordeaux region.

His writings on decoration and on the relationship between form and function in architecture had a fundamental influence on a whole new generation of architects, including all the major Art Nouveau artists: Antoni Gaudí, Victor Horta, Hector Guimard, Henry van de Velde, Henri Sauvage and the École de Nancy, Paul Hankar, Otto Wagner, Eugène Grasset, Émile Gallé, and Hendrik Petrus Berlage. He also influenced the first modern architects, Frank Lloyd Wright, Mies van der Rohe, Auguste Perret, Louis Sullivan, and Le Corbusier, who considered Viollet-le-Duc as the father of modern architecture. English architect William Burges claimed that "We all cribbed on Viollet-le-Duc even though no one could read French".

Denis of Paris (Latin: Dionysius) was a 3rd-century Christian martyr and saint. According to his hagiographies, he was bishop of Paris (then Lutetia) in the third century and, together with his companions Rusticus and Eleutherius, was martyred for his faith by decapitation. Some accounts placed this during Domitian's persecution and incorrectly identified St Denis of Paris with the Areopagite who was converted by Paul the Apostle and who served as the first bishop of Athens. Assuming Denis's historicity, it is now considered more likely that he suffered under the persecution of the emperor Decius shortly after AD 250.

Denis is the most famous cephalophore in Christian history, with a popular story claiming that the decapitated bishop picked up his head and walked several miles while preaching a sermon on repentance. He is venerated in the Catholic Church as a patron saint of both France and Paris and is one of the Fourteen Holy Helpers. A chapel was raised at the site of his burial by a local Christian woman; it was later expanded into an abbey and basilica, around which grew up the French city of Saint-Denis, now a suburb of Paris.