Considered by many to be the most beautiful woman in the world at the time, Agnes caught the eye of King Charles VII of France, who quickly made her his mistress. She was the first to be the acknowledged mistress of the king and the first to hold this semi-official position which was later to be of great importance in the monarchy.
Her beauty, enhanced by her intelligence and wit, so captivated the king that he gave her wealth, castles and property, giving her a status almost equal to that of the queen’s. These actions and his open acknowledgement of Agnes as his mistress scandalized the French people while her strong influence over the king and extravagant tastes stirred up jealousies and intrigues that earned her a number of powerful enemies.
She had three daughters with the king and while pregnant with their fourth child journeyed in midwinter to join him at Chinon, where she suddenly died at age 28, days after the child was born. The baby died shortly thereafter. Her death was attributed to dysentery, but a forensic investigation of her bones in 2004 revealed the cause of death to be mercury poisoning, leading to speculation that she was murdered. The two prime suspects were Charles’s son, the Dauphin and future King Louis XI, and French minister Jacques Couer. However, as mercury was used in cosmetics and also as a cure for worms at that time, accidental death cannot be ruled out.
Legends have grown up around her, including one that she carried on the work of Jeanne D’Arc and encouraged Charles to invade Normandy. This has largely been disproved. Agnes’ likeness was also used for the Queen of Diamonds on French playing cards.
It is also noted that her cousin, who greatly resembled her, took her place as the king’s mistress after her death.