Excavations in 1873 brought to light an ancient pagan cemetery, a pit in the center of the apse containing 27 nails assigned to the coffins of the two martyrs and reveal that four church buildings were successively below the basilica.

[2] According to tradition, their bodies are placed, 21 years after their death, in a gray marble sarcophagus, measuring 2.25 meters long and 75 centimeters wide.

The relics then attract pilgrims, requiring the creation of a "guard of honor" consists of the monks of St. Martin.

[3] 16 March 1739, the foundation stone of the reconstruction is by Jean-Marie de Trevelec, adviser to the Parliament of Brittany and his wife Françoise Charrette.

[4] According to the local director of public safety, the disaster happened accidentally while two roofers working on the refurbishment of the building, repairing a lead gutter with an oxy-fuel torch.

[8] In March 2019 it was expected that the restoration works would be completed in Spring 2021,[9] and the basilica opened on 29 August 2021.