» RELATED: 4 unusual ways to celebrate Valentine's Day in Atlanta
At the time, “Claudius the Cruel” banned all marriages and engagements under the belief that Roman men were unwilling to join the army because of their attachment to their wives and families.
But according to History.com, Valentine defied him and continued to perform secret marriages for young lovers.
One legend says that when Valentine was arrested and dragged to jail for doing so, he wrote a farewell note for his friend, the jailer’s daughter, and signed it “From Your Valentine.” This may have inspired the Valentine’s Day greeting cards of today.
» RELATED: 5 romance novels by Georgia authors to heat up your Valentine's Day
A second account lists Valentine as a bishop in what’s now Terni, Italy. Some say this bishop and the aforementioned St. Valentine who held secret marriages may refer to the same person.
Their martyrdom was honored by the Catholic Church with the celebration of St. Valentine's Day.
But that may not necessarily mean they directly inspired today’s romantic holiday traditions. In the fifth century, Pope Gelasius I combined St. Valentine’s Day with the Feast of Lupercalia, a pagan festival of love that was held Feb. 15 each year in Rome, in order to expel the pagan rituals.
During Lupercalia, the names of young women were placed in a box and drawn by men by chance. History.com describes the festival as “a bloody, violent and sexually-charged celebration awash with animal sacrifice, random matchmaking and coupling in the hopes of warding off evil spirits and infertility.”
"It was a little more of a drunken revel, but the Christians put clothes back on it. That didn't stop it from being a day of fertility and love," Noel Lenski, a historian at the University of Colorado at Boulder, told NPR.
» RELATED: Isn't it romantic: Valentine's Day events for couples around Atlanta
There was also another holiday, Galatin’s Day, that was celebrated by the Normans around the same time. Galatin meant "lover of women." Some say that because Valentine and Galatin sound alike, the holidays may have been confused for another.
While no one knows for sure which St. Valentine the holiday is based on or which previous holiday may have inspired it, it’s believed that poets like Chaucer and Shakespeare may have given some of the traditions, such as the act of card-writing on Valentine’s Day, a popularity boost.
In fact, in one of Chaucer’s poems, “The Parliament of Fowls,” he ends with a song praising St. Valentine: “providing promise that, even in the depths of winter, summer is not all that far off.”
Learn more about the history of St. Valentine and Valentine's Day at History.com.
More Valentine’s Day in Atlanta coverage: