Trying to preserve her youth, Diane de Poitiers, mistress of French King Henry II, died from drinking gold.

FORBES: Magazine Article

Their mission was not to defeat the Black Prince, who went on to take their king prisoner at Poitiers, but instead to do battle with their compatriots in Toulouse and Carcassonne who had appropriated the recipe and, they believed, were ruinously altering it.

WSJ: A Cassoulet Worth Fighting Over