The Catholic Church recognizes at least three different saints named Valentine, all of whom were martyred. One legend tells the story of a man named Valentine who served as a priest during the third century in Rome. When Emperor Claudius II decided that unmarried men made better soldiers than those with wives and children, he outlawed marriage for young men. Valentine, realizing the injustice of this law, defied Claudius and continued to officiate marriages for young lovers in secret. When Valentine’s actions were discovered, Claudius ordered that he be executed.

Other tales state that Valentine may have been killed for attempting to help Christians escape Roman prisons, where the inmates were often beaten and tortured. According to one legend, Valentine sent the first “valentine” greeting after he fell in love with a young girl—most likely the daughter of his jailor. Before his death, it is said that he wrote her a letter signed “From your Valentine,” an expression that is still used today throughout the world on February 14th. 

Although the truth behind the Valentine legends is unknown, the stories all present St Valentine as a symbol of sympathy, love and romance. By the Middle Ages, perhaps thanks to this very representation, Valentine would become one of the most popular saints in England and France.

Valentine's have been popular since the Middle Ages, though handwritten Valentine’s letters didn’t begin to appear until the years after 1400. The oldest known valentine still in existence today was a poem written in 1415 by Charles, Duke of Orleans, to his wife while he was imprisoned in the Tower of London. Several years later, it is believed that King Henry V hired a writer named John Lydgate to compose a valentine's note to Catherine of Valois. 

Today, Valentine’s Day is commonly celebrated by exchanging “Valentines” (greeting cards) or other tokens of affection like chocolates, stuffed toys or flowers. In many schools, it has become customary for young students to bring in Valentines to swap with classmates.