|Date of birth||Pouilly-sur-Meuse, canton of Stenay, arrondissement of Verdun, Meuse|
|Date of death||Jun 28, 1852 Vienna, Austria|
|Awards||Order of St. Alexander Nevsky, Order of St. George, 4th class, knight of the Military Order of Maria Theresa|
Emmanuel, count of Mensdorff-Pouilly (24 January 1777 – 28 June 1852) was an army officer in the Imperial and Royal Army of the Austrian Empire, and vice-governor of Mainz.
The Mensdorff-Pouilly family originated from the barony of Pouilly in Stenay on the river Meuse in Lorraine. Albert-Louis, Baron de Pouilly et de Chaffour, Comte de Roussy (1731–1795) and his wife Marie Antoinette (1746–1800) emigrated together with their children during the French revolution. Their sons, Albert (1775–1799) and Emmanuel (baptised at Nancy on 24 January 1777), took the name Mensdorff from a community in the county of Roussy, Luxembourg.
The brothers entered military service against revolutionary and Napoleonic France, and Albert was killed in battle. At the start of the War of the Fifth Coalition Emmanuel held the rank of major. On 13 April 1809 he was wounded while leading a company of the 8th Jäger in action near Amberg. By 23 April he had recovered enough to partake in the cavalry battles at the start of the Battle of Ratisbon. He was decorated with the Military Order of Maria Theresa for his services in the war. In 1810 he was given command of the Galician regiment of ulans „Erzherzog Carl“ Nr. 3. Serving as a commander of a cavalry brigade in Bohemia, Mensdorff-Pouilly became commander of the Fortress of Mainz. From 1829 to 1834 Mensdorff-Pouilly also served as vice-governor of Mainz. After again having served in Bohemia, in 1840 Mensdorff-Pouilly became vice-president of the Hofkriegsrat. In 1848 he retired from the army with the rank of feldmarschallleutnant. During the Revolution of 1848 Mensdorff-Pouilly was sent as a commissioner to Prague, where he tried in vain to impress on the Prince of Windisch-Grätz the necessity to avoid bloodshed.
Emmanuel von Mensdorff-Pouilly married Princess Sophie of Saxe-Coburg-Saalfeld, the daughter of Francis, Duke of Saxe-Coburg-Saalfeld, on 22 February 1804 at Coburg. Through this marriage he was the brother-in-law of King Leopold I of Belgium and the uncle of both Queen Victoria and Prince Albert of the United Kingdom, and of King Ferdinand II of Portugal.
Emmanuel and Sophie had six sons:
- Hugo Ferdinand (1806–1847)
- Alphons (1810–1894), Count von Mensdorff-Pouilly, ∞ 1. 1843 Countess Therese von Dietrichstein-Proskau-Leslie (1823–1856), ∞ 2. 1862 Countess Maria Thersia von Lamberg (1833–1876).
- Alfred Carl (1812–1814).
- Alexander (1813–1871), Fürst von Dietrichstein zu Nikolsburg 1868, was Austrian Foreign Minister and Prime Minister of Austria in the 1860s, ∞ 1857 Countess Alexandrine Maria von Dietrichstein-Proskau-Leslie (1824–1906)
- Leopold Emanuel (1815–1832)
- Arthur August (1817–1904), ∞ 1. 1853, Div. 1882 Magdalene Kremzow (1835–1899), ∞ 2. 1902 Countess Bianca Albertina von Wickenburg (1837–1912)
Emmanuel was created Count of Mensdorff-Pouilly in Vienna on 29 November 1818. In 1838, Emmanuel purchased Schloss Preitenstein in the Plzeň Region of Bohemia, which remained the property of the Mensdorff-Pouilly family until 1945.