Constructed in 1099 by little-known Italian architect Lanfranco, Duomo di Modena, also known as Modena Cathedral, is one of the more important Romanesque buildings in Europe. Dedicated to the Assumption of the Virgin Mary and Saint Geminianus, this massive structure was designated as a UNESCO World Heritage Site in 1997.

For scholars and enthusiasts of Arthurian legend, the cathedral is better known for its north gate, Porta della Pescheria ("Fish-market Gate"), and its archivolt. Decorated with high relief carvings of secular scenes from the Breton tales of King Arthur, these "Modena Archivolt" reliefs are one of the earliest depictions of the theme, featuring some characters that are not known anywhere else, whether in art or literature.

The frieze sculpture depicts the Knights of the Round Table's attack on the castle of King Maleagant, who has abducted and holds Guinevere, wife of King Arthur, captive. Here, Maleagant is identified as "Mardoc of the Dolorous Tower," and Guinevere is known as Winlogee. The knights in the Archivolt are named Artus Britani, Isdernus, Carrado, Galvagin, Che, and Galvariun, who likely correspond to Arthur, Yder, Caradoc, Gawain, Kay, and Galeshin, respectively.

This, however, remains a mere theory and there are many other opinions about Modena Archivolt. Some believe that the hero displayed is not Arthur, but Yder, while others claim that Isdernus corresponds to Sir Lancelot and not Yder. In spite of the characters' names, some also claim that the scene is not Arthurian at all, but something else.

There is also Burmalt, a knight serving King Mardoc and an otherwise unknown character in Arthurian lore. He may be related to Durmart, the King of Gaul whose adventures are told in an early 13th-century Old French romance titled Durmart le Galois. Another mystery that surrounds the carving is that it features one unnamed knight, whose identity is still unknown.