The House of Windischgrätz , also spelled Windischgraetz, is a Slovenian-Austrian aristocratic family, descending from Windischgrätz in Lower Styria (present-day Slovenj Gradec, Slovenia). The noble dynasty serving the House of Habsburg achieved the rank of Freiherren in 1551, of Imperial Counts in 1682 and of Princes of the Holy Roman Empire in 1804. The family belongs to high nobility.

According to the Almanach de Gotha, the family was first recorded in 1242. They temporarily served as ministeriales of the Patriarchs of Aquileia, owners of Windischgrätz until the mid 14th century. One Conrad of Windischgracz (d. 1339) acted as a Habsburg administrator in the Habsburg Duchy of Styria from 1323 onwards. The family owned Thal, Styria a former Von Graben possession, between 1315 and 1605.

In 1574 the dynasty obtained Inkolat in Bohemia; later, however, several members converted to Lutheranism and lost their estates in the course of the Thirty Years' War. The Austrian diplomat Gottlieb of Windischgrätz (1630–1695) again converted to Roman Catholicism in 1682 and was elevated to the rank of Count of the Holy Roman Empire by Leopold I, Holy Roman Emperor, in the same year. In 1693 his son Ernest Frederick (1670–1727) acquired Červená Lhota Castle in Southern Bohemia, which his descendant Joseph Nicholas of Windisch-Graetz (1744–1802) had to sell in 1755.

In 1781 the family bought their new main seat, the West Bohemian Tachov. Count Alfred Candidus Ferdinand zu Windischgrätz (1787–1862) became the representative of the emperor at the Reichstag and was elevated to the rank of Fürst (Prince of the Holy Roman Empire) in 1804. In order to obtain imperial immediacy (and be himself a voting member of the Imperial Diet), he acquired the small imperial territories of Siggen and Eglofs in Southern Germany. This principality however was mediatized to the Kingdom of Württemberg only two years later, when the Confederation of the Rhine was established. Prince Alfred I later became a Field Marshal in the Austrian army.

Alfred and his brother Weriand were both created Princes of the Austrian Empire in 1822, with Alfred and his successors being the first line of Princes of Windischgrätz (primogenitur), and Weriand and his successors being the second line (secundogenitur).^[1] Alfred acquired the former monastery at Kladruby (Tachov District). His grandson Alfred III, Prince of Windischgrätz, was an influential politician. He was succeeded by his nephew Ludwig Aladar, the owner of Sárospatak Castle, Hungary.

Weriand, with the help of the rich dowry of his mother, Maria Leopoldine of Arenberg, acquired numerous castles in what is now Slovenia. After World War II, the estates in the Czechoslovak Republic as well as in Hungary and Yugoslavia were confiscated by communist regimes. The estate of Siggen is still owned by the elder line.

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  Štěkeň Castle
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  Kladruby Abbey
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  Sárospatak Castle, Hungary
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  Palais Windisch-Graetz, Vienna

Great Britain's Princess Michael of Kent is descended from this family through her maternal grandmother, while her husband Prince Michael of Kent is a first cousin once removed of Archduchess Sophie Franziska of Austria, Princess of Windisch-Graetz.

Joseph Nicholas of Windischgrätz (1744–1802) was the father of both of the men whose lines are given below.

Gules, a wolf's head couped argent.^[3]

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  Original coat of arms of the family
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• Joseph Nicholas of Windischgrätz (1744–1802), chamberlain of Marie Antoinette
• Alfred I, Prince of Windischgrätz (1787–1862), Austrian Field Marshal
• Alfred II, Prince of Windischgrätz (1819–1876), Austrian Feldmarschall-Lieutenant
• Alfred III, Prince of Windischgrätz (1851–1927), Austrian statesman
• Princess Marie of Windischgrätz (1856–1929), married Duke Paul Frederick of Mecklenburg in 1881
• Prince Otto Weriand of Windischgrätz (1873–1952), married Archduchess Elisabeth Marie of Austria
• Princess Stephanie of Windischgrätz (1909–2005), daughter of Prince Otto Weriand of Windisch-Graetz
• Stéphanie Windischgrätz (b. 1939), daughter of Prince Franz Joseph of Windisch-Graetz (son of Prince Otto Weriand)
• Mariano Hugo, Prince of Windischgrätz (b. 1955), married Archduchess Sophie Franziska of Austria in 1990
• Prince Arnold zu Windischgrätz (1929–2007), Lutheran pastor
• Princess Katalin zu Windischgrätz (b. 1947), Hungarian designer

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  Haasberg Mansion ruins
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  Luegg - Predjama Castle, Postojna
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  Podstreda Castle
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  Bogenšperk Castle
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  Trebnik Mansion, Slovenske Konjice
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  Oplotnica Mansion, Oplotnica
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  Žiče Charterhouse
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  Logatec Mansion
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  Bizeljsko Castle
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  Strmol Mansion, Rogatec

• Marek, Miroslav. "Family tree of the Windisch-Graetz family". Genealogy.EU.