According to the 1962 Missal of Saint John XXIII the Extraordinary Form of the Roman Rite, February 14th is the feast of Saint Valentine. He was a priest of Rome, (some sources say he was even a bishop), who was beheaded in about 273 A.D.
Pope Julius I built a basilica on the Flaminian Way, believed to be the site of his martyrdom.
Greater love hath no man than that he lay down his life for his friends. (Jn1:13)
During the time of Claudius II, a decree was issued which forbid marriage. Saint Valentine defied this decree and urged young lovers to come to him in secret so that he could join them in the Sacrament of Matrimony. Eventually he was discovered by the Emperor, who had Valentine arrested and imprisoned.
Saint Valentine held steadfast in his Faith and in turn attempted to convert Claudius to Christianity, at which point the Emperor condemned him to death.