The earliest version of the story of St. Valentine dates back to ancient Rome and the pagan festival of Lupercalia. Shepherds prayed to the god Lupercus to watch over their flocks. Every year in February, the Romans would repay the god’s with a festival, which doubled as a celebration of fertility and the onset of Spring. Newlywed women would be whipped by februa (strips of goat skin and the derivation of our word February) to purify their bodies in preparation for childbirth.
The high point of the celebration of Lupercalia came on February 14 with an erotic tribute to Juno Februata, the goddess of feverish love. The names of maidens were drawn at random by young men and the resultant couple would become partners at the feast and even for life.
Saint Valentine, officially known as Saint Valentine of Rome, is a third-century Roman saint widely celebrated on February 14 and commonly associated with "courtly love."
The emperor Aurelius had imprisoned Valentine in 272 AD for continuing to marry Christian soldiers, despite royal decree. In prison, the bishop cured his jailer’s daughter of blindness and the pair fell head over heels in love. Ultimately, their desires were frustrated as the bishop was executed on February 14 the following year. On the eve of his death, the condemned man sent a passionate letter to his beloved, signed simply ‘your Valentine’.
Valentine's Day was most likely created by the Catholic church to overpower the pagan holiday, Lupercalia.
As time progressed more and more traditions connected to St. Valentine became the more commercialized Valentine's Day of now with gifting of red roses, bouquets, heart shaped boxes of chocolates and Valentine Card exchanges.