Many kings were mad
Caligula of Rome had his father, mother and two brothers killed to become emperor. Nero had his mother and first wife killed. These two emperors were hated so much by the people that all references to them were deleted from official Roman documentation.
The first French king, Clovis II, went mad after steeling the arm of a martyr. His great-grandson, Childeric III was known as “the idiot”. The mother of Louis IX complained that he was “not sound of mind”. And his younger son, Robert of Clermont went mad after being hit on the head with a sledge hammer.
Charles VI, called Charles the mad, ruled France from 1380 to 1415. At stages, he believed that he was made of glass and inserted iron rods into his clothing to prevent him from breaking.
The Habsburg Kings of Spain descended from Queen Juana The Mad of Castile, who was mentally unstable. Her ancestors increased her inheritance by inbreeding. These incestuous marriages resulted in the mentally and physically handicapped King Carlos II of Spain, who had an enormous, misshapen head, and a chin exaggerated to almost caricature-like proportions rendering him unable to chew and barely able to speak.
Several British kings went mad as a result of a blood disorder that causes gout and mental derangement. The most famous was Mad George III, who ruled England in the 18th Century. George was afflicted with porphyria, a maddening disease which disrupted his reign as early as 1765. Several attacks strained his grip on reality and debilitated him in the last years of his reign. He died blind, deaf and mad at Windsor Castle on 29 January 29 1820. In those years, the British Princess Caroline Mathilda married, at age 15, the deranged Christian VII of Denmark.
The United States briefly enjoyed the services of a monarch, Emperor Norton I, who proclaimed himself Emperor of the United States and Protector of Mexico in 1859. He had all his “state proclamations” published in San Francisco’s newspapers and wrote letters that were seriously considered by Abraham Lincoln and Queen Victoria.
Sun-worshipping Aztecs celebrated the inauguration of Ahuitzol in 1486 by offering the hearts of 80,000 prisoners, presumably to show that their new king could sacrifice more than any of his predecessors.