Numerous early Christian martyrs were named Valentine. The Valentines honored on February 14 are Valentine of Rome (Valentinus presb. m. Romae) and Valentine of Terni (Valentinus ep. Interamnensis m. Romae). Valentine of Rome was a priest in Rome who was martyred about AD 269 and was buried on the Via Flaminia. His relics are at the Church of Saint Praxed in Rome, and at Whitefriar Street Carmelite Church in Dublin, Ireland.
Valentine of Terni became bishop of Interamna (modern Terni) about AD 197 and is said to have been martyred during the persecution under Emperor Aurelian. He is also buried on the Via Flaminia, but in a different location than Valentine of Rome. His relics are at the Basilica of Saint Valentine in Terni (Basilica di San Valentino).
The Catholic Encyclopedia also speaks of a third saint named Valentine who was mentioned in early martyrologies under date of February 14. He was martyred in Africa with a number of companions, but nothing more is known about him.
No romantic elements are present in the original early medieval biographies of either of these martyrs. By the time a Saint Valentine became linked to romance in the 14th century, distinctions between Valentine of Rome and Valentine of Terni were utterly lost.
In the 1969 revision of the Roman Catholic Calendar of Saints, the feast day of Saint Valentine on February 14 was removed from the General Roman Calendar and relegated to particular (local or even national) calendars for the following reason: “Though the memorial of Saint Valentine is ancient, it is left to particular calendars, since, apart from his name, nothing is known of Saint Valentine except that he was buried on the Via Flaminia on February 14.” The feast day is still celebrated in Balzan (Malta) where relics of the saint are claimed to be found, and also throughout the world by Traditionalist Catholics who follow the older, pre-Second Vatican Council calendar. February 14 is also celebrated as St Valentine’s Day in other Christian denominations; it has, for example, the rank of ‘commemoration’ in the calendar of the Church of England and other parts of the Anglican Communion.(en.wikipedia.org/wiki/Valentine’s_Day)