Duke of Richelieu was a title in the peerage of France

Peerage of France

The Peerage of France was a distinction within the French nobility which appeared in the Middle Ages. It was abolished in 1789 during the French Revolution, but it reappeared in 1814 at the time of the Bourbon Restoration which followed the fall of the First French Empire...

. It was created on 26 November 1629 for cardinal Richelieu who, as a clergyman, had no issue to pass it down to. It instead passed to his great-nephew, Armand Jean de Vignerot

Armand Jean de Vignerot du Plessis

Armand Jean de Vignerot du Plessis, 2ème duc de Richelieu was a French sailor and nobleman.-Life:The great-nephew of Cardinal de Richelieu , he became a general of the gallies in 1642. He was sent to Naples, which had risen up against the Spanish and proclaimed the Neapolitan Republic...

, grandson of his elder sister Françoise (1577–1615), who had married René de Vignerot, lord of Pontcourlay († 1625).

Armand Jean de Vignerot added the cardinal's surname of du Plessis to his own, took the cardinal's coat of arms (d'argent à trois chevrons de gueules « sans meslange d'aulcunes autres ») and received the titles of duke of Richelieu and peer of France by letters patent in 1657.

Two new reversions of the title occurred in 1822 and 1879. In effect, Armand Emmanuel du Plessis, duc de Richelieu died without an heir, but he gained permission for the title of duke of Richelieu to pass to the son of his half-sister Simplicie, daughter of Antoine-Pierre de La Chapelle de Saint-Jean de Jumilhac, with reversion to the descendents of his younger brother should he die without a male heir - meaning that, in effect, the title passed to his nephew.

The title became extinct in 1952 with the son of the 7th Duke of Richelieu and of Alice Heine

Alice Heine

Alice Heine , styled HSH The Princess of Monaco, and also The Duchess of Richelieu, was the American-born second wife of Prince Albert I of Monaco, a great-grandfather of Prince Rainier III of Monaco. Marcel Proust used her as a model for the Princesse de Luxembourg in In Search of Lost Time...

 (1858–1925). Alice was widowed in 1880 and remarried to prince Albert I of Monaco in 1889.

List of dukes of Richelieu

1. 1629–1642: Armand Jean du Plessis de Richelieu (1585–1642), cardinal, 1st duke of Richelieu, first minister under Louis XIII
   Louis XIII of France
   Louis XIII was a Bourbon monarch who ruled as King of France and of Navarre from 1610 to 1643.Louis was only eight years old when he succeeded his father. His mother, Marie de Medici, acted as regent during Louis' minority...
   
   .
2. 1657–1715: Armand Jean de Vignerot du Plessis
   Armand Jean de Vignerot du Plessis
   Armand Jean de Vignerot du Plessis, 2ème duc de Richelieu was a French sailor and nobleman.-Life:The great-nephew of Cardinal de Richelieu , he became a general of the gallies in 1642. He was sent to Naples, which had risen up against the Spanish and proclaimed the Neapolitan Republic...
   
    (1629–1715), 2nd duke of Richelieu, great-nephew of the former.
3. 1715–1788: Louis François Armand de Vignerot du Plessis (1696–1788), 3rd duke of Richelieu, marshal of France
   Marshal of France
   The Marshal of France is a military distinction in contemporary France, not a military rank. It is granted to generals for exceptional achievements...
   
   , son of the former.
4. 1788–1791: Louis Antoine Sophie de Vignerot du Plessis
   Louis Antoine Sophie de Vignerot du Plessis
   Louis Antoine Sophie de Vignerot du Plessis , duke of Fronsac, then duke of Richelieu , prince de Mortagne, marquis du Pont-Courlay, comte de Cosnac, baron de Barbezieux, baron de Coze et baron de Saugeon, was a French nobleman and general.-Life:He was the son of Louis François Armand de Vignerot...
   
    (1736–1791), 4th duke of Richelieu, son of the former.
5. 1791–1822: Armand Emmanuel de Vignerot du Plessis (1766–1822), 5th duke of Richelieu, président du Conseil and Foreign Minister, son of the former.
6. 1822–1879: Armand François Odet de La Chapelle de Saint-Jean de Jumilhac (1804–1879), 6th duke of Richelieu, nephew of the former.
7. 1879–1880: Marie Odet Richard Armand de La Chapelle de Saint-Jean de Jumilhac (1847–1880), 7th duke of Richelieu, nephew of the former.
8. 1880–1952: Marie Odet Jean Armand de La Chapelle de Saint-Jean de Jumilhac (1875–1952), 8th and last duke of Richelieu, son of the former.