In Fashioning a Romance, our hero, John Harrington has a PhD in medieval literature (well, actually it's a DPhil 'cause he's a Brit). He wrote his dissertation on Pierre Abélard, the French philosopher, theologian and logician whose writing had an enormous impact on the course of medieval thought. Despite Abélard's brilliance as a thinker and a philosopher, today he's remembered primarily for his own tragic love story.
As the story goes, Pierre Abélard met and fell madly in love with a young woman named Héloïse, and she with him. When she fell pregnant, he begged her to marry him, but Héloïse initially refused. To marry would destroy Pierre's career prospects. Eventually she did agree to marry him, provided it was a secret marriage. This secret didn't last long.
Héloïse escaped to the convent of Argenteuil in an effort to save Pierre's reputation, but her plan backfired. Her uncle, under the mistaken impression that Pierre had sent Héloïse to the convent to save his own skin, "got medieval on his you-know-what", so to speak. Mutilated and disgraced, Pierre was cast out of Paris and lived out the remainder of his life as a monk. Héloïse devoted her life to the church and went on to become the abbess of the convent.
Years later, Pierre and Héloïse began to correspond regularly - an impressive 113 of these love letters are still in existence. Those letters, particularly the ones penned by Héloïse, are quite possibly the most romantic and certainly the oldest love letters in the world.