Duke of Montmorency
Charlotte Catherine was the youngest of five children born to Louis III de La Trémoille and Jeanne de Montmorency, Duke and Duchess of Thouars, members of two of France's oldest and most powerful families. Her father's family, the La Trémoïlles, held the rank of "prince étranger" at the French court, and her father was a loyalist of the House of Valois. Her maternal grandfather, Anne de Montmorency, Duke of Montmorency, had been taken captive with King Francis I of France, at the Battle of Pavia in February 1525.