Jean IV de Brosse
Jean IV de Brosse (1505 in Lamballe – 1564) was the son of René de Brosse and Jeanne de Commines (daughter of Philippe de Commines). After the death of his father at the Battle of Pavia, he succeeded him as Count of Penthièvre. In 1533, he married Anne de Pisseleu d'Heilly, the mistress of Francis I of France, and was shortly thereafter created Count, then Duke of Étampes. However, he was greatly impoverished by the expenditures necessary to maintain their position at court. With the death of Francis I, the antipathy of Diane de Poitiers compelled Jean  to retreat to Brittany, where he had been appointed governor in 1543; she also obtained his duchy of Étampes. After the death of Henry II of France and the fall of Diane, he was able to regain the duchy, but died not long thereafter.