Élie Decazes, 1st duc Decazes and 1st Duke of Glücksbierg (duc Decazes et de Glücksbierg, 28 September 1780 - 24 October 1860), was a French statesman, known from 1815 to 1820 as 1st comte Decazes in France, 1st Duke of Glücksbierg in Denmark in 1818, and 1st duc Decazes in France in 1820 (all titles by primogeniture).
His younger brother Joseph Decazes (1783-1868) was created 1st vicomte Decazes and married in 1816 Diane de Brancalis de Maurel d'Aragon, and had issue Sophie de Decazes (1817-1904), married in 1835 to François de Carbonel, and Élie de Decazes (1822-1851), married in 1850 to Elisabeth de Mauvise de Villars, the parents of Raymond Decazes (1851-), married in 1887 to Marie Luise Koechlin (they had seven children).
Meanwhile, he had been elected deputy for the Seine (August 1815), and both as deputy and as minister he led the moderate Royalists. His formula was "to royalize France and to nationalize the monarchy." The Moderates were in a minority in the chamber of 1815, but Decazes persuaded Louis XVIII to dissolve the house, and the elections of October 1816 gave them a majority. During the next four years Decazes was called upon to play the leading role in the government.
He then passed the laws on the press, suppressing the censorship. By reorganization of the finances, the protection of industry and the carrying out of great public works, France regained its economic prosperity, and the ministry became popular. But the powers of the Grand Alliance had been watching the growth of Liberalism in France with increasing anxiety. Metternich especially ascribed this mainly to the "weakness" of the ministry, and when in 1819 the political elections still further illustrated this trend, notably by the election of the famous Abbé Henri Grégoire, it began to be debated whether the time had not come to put in force the terms of the secret Congress of Aix-la-Chapelle. It was this threat of foreign intervention, rather than the clamour of the "Ultras," that forced Louis XVIII to urge a change in the electoral law that should render such a "scandal" as Grégoire's election impossible for the future.
By this time he married secondly on 11 August 1818 Egidia de Beaupoir, Comtesse de St.-Atalaire-Glücksbierg, who died in Versailles on 8 August 1873. By her he had Louis-Charles-Élie-Amanien (1819-86), Minister of Foreign Affairs (France), Frédéric Xavier Stanislas Decazes de Glücksbierg (1823 - Paris, 26 February 1887), unmarried and without issue, and Henriette Guillermine Eugénie Decazes de Glücksbierg (23 November 1824 - Tournai, November, 1899), married on 19 April 1845 Léopold Jacques Alphonse, Baron Lefebvre.
This ended Decazes's career. In December 1821 he returned to sit in the House of Peers, when he continued to maintain his Liberal opinions. After 1830 he adhered to the July Monarchy, but after 1848 he remained in retirement. He had organized in 1826 a society to develop the coal and iron of the Aveyron, and the name of Decazeville was given in 1829 to the principal centre of the industry.