Well, Elaine, there probably were one if not more. All countries with monarchies have murderous members in their histories. However, speaking out of my hat because I'm not watching the drama, I think you should look for the name of the king in this drama (when you are watching) and look him up in wikipedia or some other online source. It should at least give you an idea if they are portraying the king correctly. I did look up the drama in Han Cinema, but they don't say which specific king you are talking about, just "17th Century Joseon Dynasty" which could be any number of people.
From Dae Jang-geum: Sun-dol: "Are you trying to dry me up and kill me? Why do you say the same things over and over every day? Rather, come and hit me once! Aigu!" But then: Dr. Lazarus: "By Grabthar's hammer, by the suns of Warvan... You shall be avenged."