Duke of Enghien
The eldest sons of the Princes of Condé used the title of Duke of Enghien, and were addressed as "Monsieur le Duc" until that style came to be pre-empted by their fathers, as Dukes of Bourbon, after 1709. The Princes of Condé were also the male-line ancestors of the branches of the Princes of Conti, which flourished 1629–1814, and of the Counts of Soissons, 1566–1641.