Duke of Montmorency
However, Emperor Napoleon III extended the title of Duke of Montmorency in 1864 to Nicolas Raoul Adalbert de Talleyrand-Périgord, second son of the 3rd Duke of Talleyrand by his wife Anne Louise Charlotte de Montmorency, who was a sister of the 6th Duke of Montmorency. His male line came to an end in 1951, when the dukedom of Montmorency again became extinct.