Each February 14, an estimated 1 Billion Valentine’s cards are sent across America (according to the Greeting Card Association), and thousands of pounds of chocolate are purchased and consumed, all in the name of love. If there’s a better reason to celebrate, I can think of none. How did this amorous exchange begin, and who is St. Valentine, anyway?

Although several St. Valentines exist in recorded history, the holiday’s namesake is St. Valentine of Rome. Pope Gelasius declared February 14 his feast day (the day of his burial) in 496. However, it was removed from the official Roman calendar in 1969, because nothing specific was known about St. Valentine.

Hence, details of his life are relegated to legend. One such legend derives from Roman emperor Claudius II, who, upon deciding that single men made better soldiers than married men, decreed that young men were forbidden to marry. St. Valentine continued to perform marriage ceremonies nonetheless, and also attempted to convert Claudius to Christianity, for which he was jailed and later executed. However, before his death, he was said to have cured his jailor’s daughter from blindness. Centuries later, a little embellishment was added to the story: before his death, Valentine wrote a note to the once-blind jailor’s daughter, signing it, “Your Valentine.” She is rumored to have planted a pink-blossoming almond at his grave, which to this day symbolizes love and friendship.

Despite its early Christian namesake, it would take almost ten centuries for the holiday’s love association to become clear. The earliest known reference to love is from the 15th century Paston Letters, in which a young woman refers to her future husband, John Paston, as her “right well-beloved Valentine.” Still, the roots of this association are unclear. Some cite the stirrings of spring and bird-mating time, and others looks towards Pagan festivals, as it was common for the Catholic Church to Christianize pre-Christian celebrations. Lupercalia was a Roman festival celebrated February 13-15, and associated with ancient fertility rites.

By the 18th century, Valentines notes and messages were exchanged en masse between friends and lovers. In 1797, a British publisher issued a guide for young men in need of suggested sentiments, called The Young Man’s Valentine Writer. The rise in commercial printing and later, a reduction a postal rates, helped spread the love. In America, the first person to capitalize on the holiday was Esther Howland of Worcester, Massachusetts. She mass-produced embossed lace cards to sell in her father’s bookstore with imported paper lace from England. The Greeting Card Association gives an annual Esther Howland Award for a Greeting Card Visionary.

Starting in the mid-1950s, it became common to include flowers and candy along with cards, as commercialization took over. Hallmark cards and heart-shaped chocolate boxes have become ubiquitous, but perhaps the best Valentine is a child’s heartfelt and homemade card. The Greeting Card Association suggests that teachers are those who receive the most Valentines.