In which century did Valentine's Day become associated with romantic love?

Valentine’s Day became associated with romantic love in the 14th century.

The earliest recorded literary association is usually linked to Geoffrey Chaucer’s The Parliament of Fowls, written in 1382. The dream vision describes birds gathering on Saint Valentine’s Day to choose their mates, connecting the feast with seasonal pairing and the ideals of medieval courtly love. Chaucer’s poem helped establish a relationship between the saint’s day and romantic affection.

The association grew in the 14th and 15th centuries rather than appearing fully formed at once. Later writers developed the tradition through Valentine poems, songs, and messages. The earliest surviving valentine is generally identified as a 15th-century rondeau written by Charles, Duke of Orléans, to his wife while he was held captive in England. Early English examples also survive in the Paston Letters.

A useful distinction is that the day originally functioned as a Christian feast honoring Saint Valentine; its romantic meaning is medieval and literary. The familiar mass exchange of cards, flowers, and confectionery became especially prominent in 18th-century England and expanded with commercial printing in the 19th century.