During the 20th century, scholars and archaeologists have long debated on the figure of St. Valentine: indeed, on February 14 two holy martyrs of the same name are recorded, priest Valentine of Rome and bishop Valentine of Terni. The assumptions are basically three:
- The first solution is the classic one, supported by the majority of scholars until a few years ago: the two saints were two separate individuals. The Valentine of Rome was a priest, martyred on February 14 under emperor Gallienus (253-268), who was buried by a Christian named Sabinilla in her own lands at the foot of the Parioli hill. These topographical indications are confirmed by a Chronograph of 354, written by Furius Dionysius Philocalus, which is the earliest mention of a martyr Valentino: here it is said that Pope Julius I built a basilica "quae appellatur Valentini" (that is called of Valentino). Moreover, the presence of a Valentino in Rome is also confirmed by the discovery, in the basilica at the foot of Parioli, of fragments of a poem where Pope Damasus had honored the martyr.
- The second hypothesis, supported by Franciscan scholar Agostino Amore starting from the mention of the "Chronograph" by Philocalus, is that a martyr Valentino of Rome never existed. Valentino would be the one who financed the construction of the basilica outside the walls under the pontificate of Pope Julius I in the mid-fourth century and that, precisely because of his donation, earned the title of saint in the 6th century.
- The third hypothesis, advanced by scholar Vincenzo Fiocchi Nicolai, is that the priest of Rome and the bishop of Terni would be the same person. Valentino from Terni came to Rome and was martyred and buried: afterwards his cult spread to his hometown, where the townspeople mentioned him as their episcopus (bishop).