The basis of it might have been a true story.
The woman is of noble descent and about 10 years older than the guy. They keep their relationship in secret because in that age the difference in their social status and also the age difference would have made them wholly incompatible in the eyes of society.
They get discovered however and they both become ostracised, the woman gets stripped of her status and wealth.
The guy can’t even get a job as a hangman (or a hangman’s assistant).
Finally the queen (?) takes pity on them and gives them a little ferry station, where they guy can ferry people across a lake or river in a boat.
One day fishermen try to rape the woman and the stable boy kills one of them. He is sentenced to be a galley slave for the murder.
The woman keeps waiting for him until she grows old. That’s when she hears that the stable boy has died and she commits suicide.