The Glass Delusion was a disorder that swept through Europe during the late medieval period with some suffers believing they were made of glass stating they were glass objects or where trapped inside glass bottles.
Charles V1 was the King of France from 3rd December 1368 to 21 October 1422. When he first came to the throne he was affectionately known as the Charles The Beloved, but later during his reign he was referred to as Charles The Mad and this is why!
During his mid-twenties he began to experience bouts of Psychosis (meaning an abnormal condition of the mind). It has been recorded that other members of his family had also suffered from mental illness with Charles directly inheriting this family ailment through his mother Joanna Bourbon who suffered nervous breakdowns herself.
Charles started to believe in 1392 that he was made of glass and refused to allow people to touch him he took to wearing reinforced clothing to protect himself. As an example he inserted iron rods into his clothes to prevent himself from breaking. He actually believed he would shatter into a million pieces if he was touched or knocked. A truly insane ruler – King Charles VI of France died, a madman, in 1422.
We must also mention the Princess who swallowed a Glass Piano – Princess Alexandra of Bavaria the 5th daughter of Ludwig I of Bavaria (aka “Mad King Ludwig” was afflicted as well; she thought that when she was a little girl she swallowed a glass piano and if she sat down it would shatter inside her and kill her! She too was clearly suffering from glass delusion.
There was another case of a glass maker from Saint Germain who believed his buttocks would shatter if he sat down so he constantly applied a cushion to his buttocks. His doctor actually managed to cure him by giving him a severe thrashing telling him it was the pain of buttock flesh not glass.
The glass delusion was widely reported in the 15th to 17th centuries, but has thankfully disappeared in modern times. “Surveys of modern psychiatric institutions have only revealed two specific (uncorroborated) cases of the glass delusion. Foulché-Delbosc reports finding one Glass Man in a Paris asylum, and a woman who thought she was a potsherd was recorded at an asylum in Merenberg.”