Mid February was traditionally the time of the Lupercian festival, an ode to the God of fertility and a celebration of sensual pleasure, a time to meet and court a prospective mate. In AD 496, Pope Gelasius outlawed the pagan festival. But he was clever to replace it with a similar celebration, although one deemed morally suitable. He needed a "lovers" saint to replace the pagan deity Lupercus.

The martyred Bishop Valentine was chosen as the patron saint of the new festival.

Saint Valentine had been beheaded for helping young lovers marry against the wishes of the mad emperor Claudius. Before execution, Valentine himself had fallen in love with his jailer's daughter. He signed his final note to her, "From Your Valentine", a phrase that has lasted through the centuries.

Pope Gelasius didn't get everything he wanted. The pagan festival died out, it is true, but he had further hoped people would emulate the lives of saints. Instead they latched onto the more romantic aspect of Saint Valentines religious life. While not immediately as popular as the more passionate pagan festival, eventually the concept of celebrating true love became known as Valentine's Day.