Valentine’s Day marks a day of celebration around the globe where flowers, chocolates and teddy bears are exchanged between loved ones, all in the name of Saint Valentine.

But who exactly is this mysterious saint, and where did these traditions surface from?

The history of Valentine’s Day and the story of its “patron saint” is covered in mystery. What we do know is that February has long been celebrated as a month of romance and that St. Valentine’s Day, as we call it today, contains traces of both Christian and ancient Roman traditions.

According to History.com, the Catholic Church recognizes at least three different saints named Valentine or Valentinus, “all of whom were martyred.”

One legend has stated that Valentine was a priest who served during the third century Rome, where Emperor Claudius II decided that single men made better soldiers than those with wives and families. Thus, outlawing marriage for young men.

Valentine quickly went against Claudius and continued his duty in performing marriages for young lovers in secrecy. However, when Valentine’s actions were discovered, Claudius ordered that he be put to death.

Others stories are seen to suggest that Valentine may have been killed due to his attempt in helping Christians escape harsh Roman prison, where they were often beaten and tortured.

According to one particular legend, an imprisoned Valentine actually sent the first “valentine” greeting himself after he fell in love with a young girl who had visited him during his confinement, according to History.com.

Before his death, it is alleged that Valentine wrote a letter signed “From your Valentine,” an expression that is used every year to this day. Although, the truth behind the Valentine legends is rather murky, where the stories all highlight his appeal as sympathetic, heroic and most importantly, a romantic figure.

By the Middle Ages, perhaps thanks to this reputation, Valentine would become one of the most popular saints in England and France.

In these two countries, in the Middle Ages, it was commonly believed that Feb. 14 was the beginning of bird’s mating season, which added to the idea that the middle of Valentine’s Day should be a day for romance.

Even Valentine greetings were popular as far back as the Middle Ages, even though written Valentine’s did not begin to appear until after 1400. The oldest known valentine that is still in existence today is a poem that was written by Charles, Duke of Orleans, in 1415 for his wife while he was imprisoned in the Tower of London (the greeting is now part of the manuscript collection of the British Library in London, England).

Only a couple years later was it believed that King Henry V hired a writer by the name of John Lydgate to compose a valentine note to Catherine of Valois.

Now, in the present day, Valentine’s Day is heavily celebrated in the United States, Canada, Mexico, the United Kingdom, France and Australia.

In Great Britain, Valentine’s Day began to be popularly celebrated around the 17th centruy. By the middle of the 18th century, it was more common for friends and lovers of all social classes to exchange smaller tokens of affection or handwritten notes. By the 1900’s, printed cards began to replace written letters due to improvements in printing technology.

Ready-made cards became an easy way for individuals to express their emotions in a time when direct expression of someone’s feelings were often discouraged. Cheaper postage rates also helped contribute to increase the popularity of sending Valentine’s Day greetings.

For America, it was not until the early 1700’s where individuals began exchanging hand-made valentines. In the 1840’s Esther A. Howland, known as the “Mother of the Valentine,” made “elaborate creations with real lace, ribbons and colorful pictures known as ‘scraps,'” according to History.com.

Today, according to the Greeting Card Association, an estimated 145 million Valentine’s Day cards are sent each year, making Valentine’s Day the second largest card-sending holiday of the year — Christmas landing at number one.