Legend has it that Valentine was a priest near Rome in about the year 270 A.D, a time when the early Christian church was subjected to significant persecution.
Valentine's role as a Priest was to help Christians to escape persecution, and to provide them the sacraments, such as marriage, which was outlawed by the Roman Empire at that time.
While records are scarce it seems that Valentine's persecution as a Christian included his interrogation by the then Roman Emperor, Claudius II. Finding Valentine an erudite, intelligent man, he attempted to get him to convert to Roman paganism in order to not only save his life, but then use him as a powerful foe for the rapidly growing Christian movement. Valentine refused and tried to convert Claudius to Christianity instead. Because of this, he was executed.
It's fair to ask at this point : "Why was Valentine made a saint?"
Well, while he was jailed awaiting execution, the legend was born that he performed a miracle by curing the blindness of Julia, the daughter of his jailer, Asterius. Julia and all of her father's household, family and servants, came to believe in Jesus Christ and were baptised by Valentine.
Father Valentine is said to have secretly performed many Christian weddings for Roman soldiers, who were actually forbidden to marry. Roman Emperor Claudius II believed that married men made bad soldiers.
Another legend accorded to St Valentine is his wish to remind the soldiers of God's love and to encourage them to remain faithful Christians, he is said to have cut hearts from parchment, giving them to the soldiers. This is possibly the origin of the modern tradition of hearts representing love, and especially used on cards and gifts for Valentine's Day on 14th February, his Saint's Day.
Further folklore surrounding Saint Valentine, has it that on he evening before Valentine was to be executed, he wrote the very first Valentine's card himself, and gave it to the daughter of his jailer Asterius, who was now no longer blind, signing as "Your Valentine"! This, of course, is the expression we now use today, usually when sending an anonymous card.
As stated earlier, records are scarce and quite a number of other explanations have been given for the origins of Valentine's Day.
The period 13th to 15th February was celebrated in ancient Roman times with the Festival of Lupercalia. This honoured the Roman gods of Lupercus and Faunus and the founders of Rome itself, Romulus and Remus.
The Lupercus festivities are said to have included the pairing of young women and men for one whole year until the celebration started in the following year.
Of course this was not recognised as the Valentine's Day festivities (if it was) until late in the 3rd century AD as described above.
Today, of course, celebrations of Valentine's Day around the world, has become a huge commercial activity, worth billions of dollars world-wide, especially for the greetings card industry (where it is often coined a "Hallmark Holiday") and for florists and garden centres.