What is the origin of the myth of St. Valentine?

Question

There seems to be a story floating around about St. Valentine being martyred for performing weddings. Here's a representative version:

Valentine became famous for marrying couples who were in love but couldn’t get legally married in Rome during the reign of Emperor Claudius II, who outlawed weddings. Claudius wanted to recruit lots of men to be soldiers in his army and thought that marriage would be an obstacle to recruiting new soldiers; he also wanted to prevent his existing soldiers from getting married because he thought that marriage would distract them from their work.

The thing is, St. Valentine's Wikipedia page clearly labels this as a legend. However, it seems to be prevalent (and reported as fact) on a lot of sites I consider of dubious quality, like ask.com and CBN. Even there, their stories don't agree.

One would think that if Claudius passed such a law, there would be a record of it somewhere. All I could find was Lex Papia Poppaea, which encouraged marriage. Claudius's page does indicate that he tried to get his soldiers to prevent him from marrying. Perhaps that's the germ of truth at the bottom of this story?

So I'm curious about two things here: How likely is this legend, and when did it first appear?

Answer 1

I believe that the commonly accepted answer is that our mythology of St. Valentine is first recorded in Chaucer.

The popular customs associated with Saint Valentine's Day undoubtedly had their origin in a conventional belief generally received in England and France during the Middle Ages, that on 14 February, i.e. half way through the second month of the year, the birds began to pair. Thus in Chaucer's Parliament of Foules we read:

For this was sent on Seynt Valentyne's day Whan every foul cometh ther to choose his mate.

The cited article contains additional information, including the fact that of the three Valentines who are Saints, none of them have any particular association with marriage, and some additional information about historical growth of the holiday.