Ludwig XI.
When becoming mistress of the Duke of Brittany, Louis XI of France expected her to continue to act as his spy, this time upon the Duke of Brittany. Initially, she did fulfil this expectation, but eventually, she changed her loyalties. During the war between France and Brittany, Antoinette de Maignelais sold her jewels to finance the army of Brittany against France. Upon hearing of this, Louis XI of France confiscated her property in France.