A grand duchy is a form of principality which has a Grand Duke or a Grand Duchess as head of state. An early use of the title was in Grand Duchy of Lithuania (since 14th century), Grand Duchy of Moscow, and also in Tuscany, which became a grand duchy in 1569, and remained one until 1860, when it was annexed by Piedmont-Sardinia. Between the Napoleonic Wars and World War I there were eight grand duchies in Europe: Baden, Finland, Hesse-Darmstadt, Luxembourg, Mecklenburg-Schwerin, Mecklenburg-Strelitz, Oldenburg, and Saxe-Weimar .

The title was also used in some short-lived Napoleonic creations:

• The Grand Duchy of Berg (1806-1813)
• The Grand Duchy of Würzburg (1806-1814)
• The Grand Duchy of Frankfurt (1810-1813)

Particularly following the Congress of Vienna, grand duchies became fairly common within the Germanic Confederation:

• The Grand Duchy of Hesse-Darmstadt (1806-1918)
• The Grand Duchy of Baden (1806-1918)
• The Grand Duchy of Luxembourg (since 1815)
• The Grand Duchy of Mecklenburg-Schwerin (1815-1918)
• The Grand Duchy of Mecklenburg-Strelitz (1815-1918)
• The Grand Duchy of Saxe-Weimar (1815-1918)
• The Grand Duchy of Oldenburg (1829-1918)

Today Luxembourg is the only remaining grand duchy. It has been a grand duchy since 1815, when the Netherlands became an independent kingdom and Luxembourg was handed over to the King of the Netherlands, William I. Luxembourg remained a Dutch dominion until 1890, when King William III of the Netherlands, who was also Grand Duke Guillaume III of Luxembourg, died without leaving a male heir to the Luxembourgian Grand Duchy. The throne then passed to his cousin, Duke Adolf of Nassau who became HRH Grand Duke Adolf I. The present Grand Duke of Luxembourg is Henri.

Note that a Grand Duke or Grand Duchess is not necessarily associated with a Grand Duchy; see the relevant articles for more information.

Styles and forms of address

Most often, a reigning Grand Duke was styled Royal Highness. Other members of the families differed in style. Junior members of the Grand Ducal Family of Luxembourg are also Royal Highnesses.

In Hesse-Darmstadt and Baden, however, junior members of the dynasty bore the style of Grand Ducal Highness (Großherzogliche Hoheit). For instance, prior to her marriage, Empress Alexandra of Russia was known as "Her Grand Ducal Highness Princess Alix of Hesse on the Rhine" (Ihre Großherzogliche Hoheit Alix Prinzessin von Hessen bei Rhein).

A Russian Grand Duke or Grand Duchess was an Imperial Highness.

See also

• Duchy
• Grand Duchy of Poznan
• Grand Duchy of Lithuania
• Fürst
• Nobility
• Ranks of nobility and peerage
• Titles of nobility