SEPTEMANIE DU PLESSIS, Duc DE (1766-1822) , French statesman, was born in Paris on Sept. 25, 1766, the son of Louis Antoine du Plessis, duc de Fronsac and grandson of the marshal de Richelieu (1696-1788). The comte de Chinon, as the heir to the Richelieu honours was called, was married at fifteen to Rosalie de Rochechouart, a deformed child of twelve, with whom his relations were never more than formal. After two years of foreign travel he entered the Queen's dragoons and next year received a place at court, where he had a reputation for Puritan austerity. He left Paris in 1790 for Vienna, and in company with his friend Prince Charles de Ligne joined the Russian army as a volunteer, reaching the Russian headquarters at Bender on the 21st of November. By the death of his father in February 1791, he succeeded to the title of duc de Richelieu. He returned to Paris shortly afterwards on the summons of Louis XVI., but he was not sufficiently in the confidence of the court to be informed of the projected flight to Varennes. In July he obtained a pass port from the National Assembly for service in Russia. In 1803 he became governor of Odessa. Two years later he became governor general of the Chersonese, of Ekaterinoslav and the Crimea, then called New Russia. In the eleven years of his ad ministration, Odessa rose from a village to an important city. The central square is adorned with a statue of Richelieu (1826). A magnificent flight of nearly 200 granite steps leads from the Richelieu monument down to the harbours.
Richelieu returned to France in 1814; on the triumphant return of Napoleon from Elba he accompanied Louis XVIII. in his flight as far as Lille, whence he went to Vienna to join the Russian army, believing that he could best serve the interests of the monarchy and of France by attaching himself to the headquarters of the emperor Alexander. As the personal friend of the Russian
emperor his influence in the councils of the Allies was likely to be of great service. He refused, indeed, Talleyrand's offer of a place in his ministry, pleading his long absence from France and ignor ance of its conditions; but after Talleyrand's retirement he succeeded him as prime minister.
The events of Richelieu's tenure of office are noticed elsewhere. (See FRANCE: History.) It was mainly due to his efforts that France was so early relieved of the burden of the allied army of occupation. It was for this purpose mainly that he attended the congress of Aix-la-Chapelle in 1818. There he had been informed in confidence of the renewal by the Allies of their treaty binding them to interfere in case of a renewal of revolutionary trouble in France ; and it was partly owing to this knowledge that he resigned office in December of the same year, on the refusal of his col leagues to support a reactionary modification of the electoral law. After the murder of the duc de Berry and the enforced retirement of Decazes, he again became president of the council (Feb. 21, 1821) ; but his position was untenable owing to the attacks of the "Ultras" on the one side and the Liberals on the other, and on Dec. 12 he resigned. He died of apoplexy on May 17, 1822.
Part of Richelieu's correspondence, his journal of his travels in Ger many and the Turkish campaign, and a notice by the duchesse de Richelieu, are published by the Imperial Historical Society of Russia, vol. 54. See also L. de Crousaz-Cretet, Le Duc de Richelieu en Russie et en France (1897) L. Rioult de Neuville in the Revue des questions historiques (Oct. 1897) ; R. de Cisternes, Le Duc de Richelieu, son action aux conferences d'Aix-la-Chapelle (1898).