In the early years of his reign, Charles VI was welcomed with hopes of reform and competent guidance after sweeping out a corrupt circle of advisors. The monarchy appeared poised for a brighter chapter, and his leadership earned him the affection of many. Yet the crown soon revealed a unsettling second side. In 1392, a sudden mental crisis struck: during a military campaign, he turned on his own knights, driven by paranoia and confusion. This episode marked the start of a pattern of psychosis and fluctuating clarity that would recur for years.

The crisis intensified after the Bal des Ardents in 1393, a masquerade where Charles joined revelers dressed in perilously flammable costumes. A torch spark ignited the group, tragically killing four men and deepening the king’s mounting anxiety and instability. Amid these upheavals, one striking delusion took hold: Charles believed his body was composed of glass. He wore reinforced armor with iron supports and shied away from rapid movement or touch, fearing shards and shattering.

The glass delusion was not unique to him alone; it circulated across Europe from late medieval into early modern times, affecting nobles, scholars, and even royalty. Some interpret the phenomenon as a reflection of feeling exposed or precious in an era when glass symbolized both beauty and vulnerability. In a period when glass was rare and costly, such fears may have underscored a shared human sensitivity to fragility within a world of display and scrutiny.