In 269, there was a Christian priest and physician named St. Valentine 's in Rome, Italy. He was imprisoned by the then Roman emperor Cradius II on charges of preaching. Because Christianity was then banned in the Roman Empire. While in captivity, he cured the blind daughter of a prisoner. This increased the popularity of St. Valentine. And so the king became jealous of him and put him to death. That day was February 14th. Then, in 496, Pope St. Gelasius also declared February 14th, Valentine 's Day , in memory of the 1st Julius Valentine.