Okay, a quitessential 17th century drama and intrigue story with all the important elements (sex, crime, despotism):
The Prince, local aristocrat, bored and overstrained with his tasks to rule his fiefdom, falls in love with a beautiful, but common girl. Obsessed with winning her as his mistress (he is probably married for political reasons), he tries to discredit her father - a well-regarded but not too wealthy merchant or respected craftsman - and ruins her marriage, assuming that if her plans for the future are ruined, she better has to become his playmate.
The prince will tell the girl's fiancé that she is not as virtuous as it seems, and that she was the paramour of one off his men, a mean-spirited chevalier and famed duelist, the marriage is off. Obviously the PCs can enter here to help the fellow to challenge said duelist so that he admits to have lied about having carnal knowledge of the girl.
At the same time, the Prince tries to bancrupt the father by placing an order a very fancy order with him, that requires the father to spend a lot of his money in advance (alternatively, the Prince borrows the necessary money for that endeavour and use one of his allies to place the order) to buy the raw materials or gather the goods. Then, the Prince (or more likely, the villaineous chevalier in his services) order a sabotage (burning down the warehouse, capture the freighter that transports the goods, whatever seems to fit) and then demands his goods or his money, knowing that the father cannot deliver and has to break the contract).
Again, at this point, the PCs can get involved and find evidence for the sabotage which would allow to blackmail the Prince to repay the father and leave the family alone.
If everything goes to the Prince's plans, he will invite his soon-to-be mistress to his hunting manor/ summer palace / garden of frivol frolicking and will suggest that if she will be his misstress, he will be merciful with her father and not demand compensation for his losses. She either agrees, or more likely, commits suicide (death before dishonor and all that).
With this as a starting point, the Prince - pretty much untouchable due to his social rank and connections to the royal family, despite being a selfish and entitlted man-child - has the format to be a reoccuring villain of sorts- either because the PCs ruined his masturbation fantansies about a girl he fancied, or because the players will develop a strong dislike for him.