Duke of Montmorency was a title of French nobility that was created several times for members of the Montmorency family, who were lords of Montmorency, near Paris.
Portrait of Henri II, Duke of Montmorency
The House of Montmorency was one of the oldest and most distinguished noble families in France.
Anne de Montmorency, 1530, by Jean Clouet
Histoire généalogique de la maison de Montmorency et de Laval; par André Du Chesne (1624)