[2] It is believed that Saint Faith, a young girl from Agen, was martyred at the end of third or beginning of the fourth century,[4] in which she was tortured naked over a brazier.

[5] The first extant reference to the martyrdom of Faith exists in the late sixth-century manuscript copy of the martyrology of Jerome, who died in 420, in which her feast day is listed as 6 October.

[4] Her popular hagiography, Liber miraculorum sancte Fidis,[6] attributed to the churchman Bernard of Angers (composed between ca 1013 and after 1020), calls miracles associated with Faith joca—Latin for "tricks" or "jokes", the kind that "the inhabitants of the place call Sainte Foy's jokes, which is the way peasants understand such things.

Austrin and his new wife visit the saint's shrine, and on the third night, "when the sorrowful woman happened to blow her nose, the ring flew off without hurting her fingers, just as if it had been hurled from the strongest siege engine, and gave a sharp crack on the pavement at a great distance.

[9] The Cançó de Santa Fe, celebrating Saint Faith in 593 octosyllabic lines, is the earliest known written work in the Catalan language, set down during the reign of Ramon Berenguer I, Count of Barcelona, between 1054 and 1076 (often dated c. 1070[10]).

[17] One legend, retold in La Vie de Sainte Foy by Simon of Walsingham in the 12th century, states that during the persecutions of Christians by the prefect Dacian, Caprasius fled to Mont-Saint-Vincent, near Agen.

His change in attitude came when he witnessed an "economically charged [miracle]" in which another cleric, Odalric, claimed he was beaten by Sainte Foy.

The head itself, made of a different gold from the body—which is fashioned of thin plates over a yew wood—has been tentatively identified as an imperial portrait of the Later Roman Empire.

Thomas Hoving, former director of the Metropolitan Museum of Art, has alternately theorized that the life-size golden face is a portrait or death mask of Charlemagne.