The phenomenon that was TV’s Game of Thrones has nothing on the games that Russian Czar Peter I, known as Peter the Great, played throughout his reign. Through a series of wars, he expanded Russia’s land and power. He ruled with the proverbial iron hand for over 40 years in the late 1600s/early 1700s, and he struck fear in the hearts of his enemies…and his friends. Peter was ruthless, but he could also be incredibly modern and forward-thinking in his decisions.

An example of this is the building of St. Petersburg. Peter built the city as an example of the modern, western-style metropolis that had all the latest and most up-to-date technology. He introduced the first newspaper to Russia. He brought universities and culture to the nation. But it was his personal life that has many historians comparing him to the fictional characters in the Game of Thrones stories.

You see, Peter had a wife…and several mistresses. Peter’s liaisons produced over a dozen children, three of which lived to adulthood (and at least one of which the czar himself had poisoned for suspected treason). One of Peter’s favorite consorts was a woman named Anna Mons. And Peter’s second wife, Catherine, had Anna’s brother, Willem Mons, as a “private secretary” in her chambers. There were rumors that Catherine and Willem were having an affair. Are you keeping all this straight? If you’re Peter, you find out that your wife is having an affair with your mistress’s brother. Well, you can imagine how that news was received by Czar Peter. What games were Catherine and Mons playing? And it didn’t help that Willem Mons was described by contemporaries as one of the most handsome men in Russia.

Well, Peter brought Willem up on charges of embezzlement. Mons was imprisoned and eventually beheaded by the state on the steps of a government building in St. Petersburg. What happened next is not exactly clear, but the story is that the relationship between Peter and Catherine grew incredibly icy after the beheading. The pair were rarely seen in public together, and, when they were seen together, they rarely spoke. It seems that the beheading of Willem Mons scared Catherine into silence and, perhaps, she was also mourning the man she really loved.

But the really sick, twisted part of this story is that Catherine and Peter had a tangible reminder of Catherine’s supposed infidelity. While it is beyond doubt that she trusted Willem and took him into her confidence, we are only supposing that the two were lovers. But, if they were not, Peter certainly thought they were. And Peter didn’t play games.

And that’s why Peter ordered that on the nightstand by Catherine’s bed for the rest of his life, there would be placed a jar, filled with brine, and inside the brine rested the severed head of Willem Mons.