As an undergraduate, on a tour of Europe, I happened to step into the church where Saint Valentine’s head was kept. The tour guide told us a (likely fictitious) story about Saint Valentine performing forbidden marriages for persecuted Christians under the Roman emperor Claudius Gothicus (possibly 269-270 AD). Valentine was then imprisoned and beheaded in Rome.
His saint’s day has since become a celebration of romance. But earlier medieval accounts of Valentine’s life contain no mention of his association with love.