The eldest son of François de La Trémoïlle, Louis III (1521-1577), was the first of his family to obtain ducal status when Charles IX conferred that honor upon him in 1563. His son with Jeanne de Montmorency, Claude (1566-1604), had the dukedom elevated into a peerage in 1595, although it was not registered as hereditary in the "Parlement" until 1599. He had converted to Protestantism and fought for the Huguenots during the French Wars of Religion at the battles of Coutras in 1587, Ivry in 1590 and Fontaine-Française in 1595, and at the sieges of Paris and Rouen. In 1598 he married Charlotte Brabantine of Orange-Nassau (1580-1631), daughter of the Protestant Dutch leader William the Silent. Claude's sister, Charlotte Catherine de La Trémoille (d. 1619), married Henri I de Bourbon, prince de Condé (1552-1588) in 1586, but when he died suddenly six months before the birth of their only son in September 1588, she was imprisoned on suspicion of having poisoned her husband to prevent the child's rejection as a bastard, although the king recognized the child as "premier prince du sang" and heir presumptive to the crown until the birth of his own son, the future Louis XIII, in 1601.