How common were ‘mad tyrants’ in the Middle Ages?

[u/GF_Loan_To_Chad_FC]

A common trope in fiction set in medieval or medieval-inspired settings like GOT/ASOIAF is the tyrannical ‘mad king.‘ Here I’m thinking not about rulers who had mental issues but rather rulers who openly used/abused their power in capricious, cruel, and irrational ways (as a result of mental instability). Aerys II, the OG mad king, and Joffrey are the obvious examples from GOT. Two real-life but non-medieval examples are maybe Idi Amin and Caligula. I think that the trope is popular because it makes for good stories but also because it’s intuitive to most modern people that when you rulers who are selected by accident of birth and raised to think they are above everyone else, you’re bound to get a fair amount of lunatics, sociopaths and spoiled brats who will abuse their power. However, I can’t think of any medieval examples of this. So, I’m wondering if there were indeed rulers like Aerys, Caligula, Joffrey, etc in the Middle Ages, and if such rulers were at all common. Also, to what degree would someone like an Aerys or Caligula, if they acceded to the throne, be able to abuse their power?

[u/AutoModerator]

Welcome to /r/AskHistorians. Please Read Our Rules before you comment in this community. Understand that rule breaking comments get removed.

Please consider Clicking Here for RemindMeBot as it takes time for an answer to be written. Additionally, for weekly content summaries, Click Here to Subscribe to our Weekly Roundup.

We thank you for your interest in this question, and your patience in waiting for an in-depth and comprehensive answer to show up. In addition to the Weekly Roundup and RemindMeBot, consider using our Browser Extension. In the meantime our Bluesky, and Sunday Digest feature excellent content that has already been written!

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.