St. Valentine: Who was this man?

St. Valentine was a priest who lived before Christ in the era of emperor Claudius. This emperor had the idea of creating a super army but, for this, he needed many soldiers to volunteer. As this didn't happen, the emperor decided to forbid marriages so as to have soldiers without a family who would easily be part of his army and fight in the battles.
Nobody liked this decision and Valentine went on celebrating marriages in secret. One day, he was caught: The young couple run away but he went to jail. Many couples showed their solidarity by throwing notes or flowers through the window and the guard's daughter became his friend. On the day he was going to be killed, he wrote her a letter signed with "love from Valentine".
Tradition says that from this day on people exchange love notes on the day Valentine was killed (14th February) to remember and celebrate his courage and determination to protect love.