UNITED STATES — The celebration of Valentine’s Day, which happens every year on February 14, is all about spreading the love.

According to National Geographic, the holiday got its name from a man named Valentine. Valentine was a Roman priest who helped couples secretly get married.

According to the story, Emperor Claudius II of Rome—who reigned from the year 268 A.D. to 270 A.D.—banned marriage because he thought unmarried men made better soldiers. Valentine secretly performed marriage ceremonies until he was caught and later killed on February 14 of the year 270 for defying the emperor. Before Valentine died, he supposedly wrote the first-ever “valentine” to his jailer’s daughter, with whom he’d fallen in love. Later, in the 5th century, Pope Gelasius I declared the day of his death as St. Valentine’s Day, following his canonization.

Several love traditions and/or myths have been associated with St. Valentine, and have evolved over the years.

According to History.com, some claim that the Christian church celebrated St. Valentine’s feast day in the middle of February in an effort to “Christianize” the pagan celebration of Lupercalia. Lupercalia was a fertility festival dedicated to Faunus, the Roman god of agriculture, as well as to the Roman founders Romulus and Remus.

During the Middle Ages — which lasted from the 5th to 15th centuries in Europe — it was believed that February 14 was the beginning of birds’ mating season. The English poet Geoffrey Chaucer was the first to record St. Valentine’s Day as a day of romantic celebration in his 1375 poem “Parliament of Foules.” He wrote, “For this was sent on Seynt Valentyne’s day / Whan every foul cometh ther to choose his mate.” It is believed that Chaucer inspired people to exchange handmade cards with love notes inside, according to History.com.

In a tradition that’s also tied to the Middle Ages, South African women would wear hearts on their sleeves. Girls pinned the names of their crushes on their shirtsleeves, sometimes revealing themselves as secret admirers to their sweethearts.

According to the British Library, the oldest known valentine still in existence today was a poem written in 1415 by Charles d’Orléans, the grandson of King Charles V of France, which he wrote after he was freed from imprisonment during the Battle of Agincourt.

His poem refers to the courtly practice of holding a lottery on St Valentine’s Day in which everyone was assigned a partner to be their “Valentine” for the year. At the time, knights were supposed to devote themselves to the service of a married lady. In the poem, d’Orléans excuses himself from the custom, apologetically telling his allotted Valentine that he’s too old and tired.

 The first line of the poem is interpreted as, “Je suis desja d’amour tanné / Ma tresdoulce Valentinee (I’m already wearied by love, my very sweet Valentine).”

Today, billions of dollars are spent on Valentine’s Day cards and gifts each year around the world.

Leigh Reagan Smith is a wildlife and community news reporter. Originally a documentary filmmaker, she has lived in the valley since 1997. Leigh enjoys skiing, horseback riding, hiking, mountain biking and interviewing interesting people for her podcast, SoulRise.