Saint Valentine's Day is February 14th. So who is St. Valentine and why is today celebrated?  Excerpt from www.stvalentinesday.org

Defiance by Saint Valentine
The pairing of young boys and girls did set the mood of the Valentine's Day Festival as we know today. But it was actually due to the efforts and daring of a priest St Valentine that the festival got its name and clearer meaning. The story goes that during the reign of Emperor Claudius II Rome was involved in several bloody and unpopular campaigns. Claudius found it tough to get soldiers and felt the reason was that men did not join the army because they did not wish to leave their wives and families. As a result Claudius cancelled all marriages and engagements in Rome. A romantic at heart priest of Rome, Saint Valentine, defied Claudius's unjustified order. Along with Saint Marius, Saint Valentine secretly married couples. When his defiance was discovered, Valentine was brutally beaten and put to death on February 14, about 270 AD. After his death Valentine was named a Saint.

According to another version of legend Valentine was killed because he attempted to help Christians escape from the Roman prison as they were being tortured and beaten there. Yet another popular version of the legend states that while in prison Valentine or Valentinus fell in love with the jailer's daughter who visited him during confinement. Before his death Valentine wrote a farewell letter to his sweetheart from the jail and signed 'From your Valentine'. The expression became quite popular amongst love struck and is still very much in vogue.

By the Middle Ages, Valentine assumed the image of heroic and romantic figure amongst the masses in England and France. Later, when Christianity spread through Rome, the priests moved Lupercalia from February 15 to February 14. Around 498 AD, Pope Gelasius declared February 14 as St. Valentine's Day to honor the martyr Valentinus and to end the pagan celebration.