Royalty's Strangest Characters: Extraordinary But True Tales from 2,000 Years of Mad Monarchs and Raving Rulers (Strangest series);

Just as the monarchy has been hereditary in many countries, so insanity has been hereditary in many monarchs. Here are 2,000 years of crazy kings and potty potentates, including such infamous characters as Caligula and Vlad the Impaler.