The butte owes its particular religious importance to the text entitled "Miracles of Saint-Denis", written before 885 by Hilduin, abbot of the monastery of Saint-Denis, which recounted how Saint Denis, a Christian bishop, was decapitated on the hilltop in 250 AD on orders of the Roman prefect Fescennius Sisinius for preaching the Christian faith to the Gallo-Roman inhabitants of Lutetia. According to Hilduin, Denis collected his head and carried it as far as the "fontaine Saint-Denis" (on modern "impasse Girardon"), then descended the north slope of the hill, where he died. Hilduin wrote that a church had been built "in the place formerly called Mont de Mars, and then, by a happy change, 'Mont des Martyrs'."