On 13 March 1569, in the Third War of Religion, Françoise's husband was slain at the Battle of Jarnac when the Huguenot army was defeated by the Catholic forces led by Marshal Gaspard de Saulx, sieur de Tavannes, and the Duke of Anjou, who would later rule as King Henry III. Queen Elizabeth I of England, herself being Protestant, promised to lend money to the Huguenot faction, however, Françoise was required to pledge her jewels as security.