St. Valentine's Day is the result of the unlikely combination of a Pagan celebration and a Saint of the Catholic Church. In Pagan history, February 14th and 15th was the celebration of Lupercalia, a festival held honoring Juno, Queen of the Roman Gods and Goddesses. Juno was the Goddess of Women and Marriage. During the festival of Lupercalia a lottery was held where young men drew names of women out of a box. The name they drew was the name of their sweetheart for the entire year. The couple would exchange gifts and often they would fall in love.
Many legends are told of St. Valentine and the origin of Valentine's Day. One story is of how Valentine, a believer in love, went against the Roman emperor of the time, Claudius II by marrying couples secretly. Claudius II believed strongly that single men made better soldiers than married men; therefore he set out to build a strong military of single men. When Claudius II learned of the secret marriages St. Valentine was conducting, he jailed Valentine and later executed him on February 14th, now established as Valentines Day.
Another legend states that Valentine was an imprisoned man who fell in love with a forbidden woman, the jailors daughter. He wrote letters to his love proclaiming his love to her and he signed these letters with the popular phrase used today, "Your Valentine."
Some people believe St. Valentines Day was celebrated in the middle of February in honor of his death which occurred around 270 A.D. Other's think St. Valentines Day was started to "christianize" the Lupercalia festivals. No matter what the reason was, February 14th was officially recognized as St. Valentines Day around 498 A.D. by Pope Gelasius.
Today we do not use the tradition of the Lupercalia lottery; however that ancient tradition has some symbolic meaning. Choosing a random name out of a box symbolizes the idea that one cannot choose who they fall in love with. Cupid is a sneaky little God.