The Decameron - Giovanni Boccaccio

This fascinating collection of stories, straddling the end of the Middle Ages and the start of the Renaissance, was a profound influence on The Canterbury Tales. The striking thing to the modern reader is the joie de vivre exhibited by the characters, particularly in the sexual realm, and the concomitant disregard for all church authority.

I bought my copy from a second hand bookshop in New York City in April 1997, a mere 15 years ago. Well, I got around to it eventually.