Valentine’s Day is a holiday celebrated on February 14 every year. Across some places around the world, including the U.S. candy, flowers, and gifts are exchanged between loved ones all because of someone named “St. Valentine.”

St. Valentine was a priest who served during the third century in Rome, Italy. When a man named Emperor Claudius II decided that single men made better soldiers than one with wives and families, he stopped marriages from being continued for young men. Valentine did not let that stop him, so he defied Claudius and continued to perform marriages for lovers in secret. When Claudius discovered Valentines actions, he ordered that he be put to death. People still insisted that Saint Valentine was the true namesake of the holiday.

Some might believe that Valentine’s Day is celebrated in the middle of February to celebrate the death of St. Valentine, others believe it’s because the Christian Church may have decided to put St. Valentine’s feast day in the middle of the month in effort to “Christianize” the celebration of Lupercalia (which was a fertility festival honoring Faunus, the Roman god of agriculture, and to the Roman founders Romulus and Remus).

Source: https://www.history.com/topics/valentines-day/history-of-valentines-day-2