Duke of Chaulnes

The title of Duke of Chaulnes (French: Duc de Chaulnes), a French peerage, is held by the d'Albert family beginning in 1621.

The Duchy of Chaulnes was established by a letters patent of January 1621, registered on 6 March 1621 at the Parliament of Paris in favour of a younger brother of Charles d'Albert, Duke of Luynes (1578–1621), Honoré d'Albert (1581–1649), Marshal of France in 1619, known as the Marshal de Cadenet.

On January 14, 1620, he married Charlotte Eugénie d'Ailly who was the heir to a family holding the titles of Count of Chaulnes (created in December 1563), Vidame d'Amiens and Baron de Picquigny. The marriage contract stipulated that their heirs would take the name and arms of Ailly, which indeed happened; their children took the surname of d'Albert d'Ailly.

The first Duke of Chaulnes had several sons; only one was married, however, and he himself sired only girls. He became the second duke, and when he died in 1653, lacking male progeny, the title passed to a minor who became the third Duke. In 1667, to avoid the title passing into disuse, the third duke, at the request of his mother, Charlotte d'Ailly, named his heir as the Duke of Chevreuse, second son of the Duke of Luynes. This was stipulated in the Duke of Chevreuse's marriage contract which also stipulated that the title would pass to the youngest child of the marriage and, in case the male line subsequently ended, to the youngest of that name who held the arms of the d'Albert family. Thus two distinct houses were created: Luynes, which the Duke of Chevreuse inherited from his father in 1688, and Chaulnes, which remained distinct and separate from the former until the direct line of inheritance came to an end. In that case, the two houses should be reunited until it was possible to separate them again.

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