Duchy of Oldenburg

Duchy of Oldenburg Herzogtum Oldenburg (German)
1774–1810
Coat of arms
Location of the later Duchy of Oldenburg within the Holy Roman Empire (upper left, light green)
Capital	Oldenburg
Government	Feudal monarchy
Duke of Oldenburg
• 1774–85	Frederick August I (first duke)
• 1785–1810     (restored 1813–23)	William (last duke before French annexation)
History
• Created on breakup of Saxony	1091
• Raised to duchy	1774
• Annexed by France	1810
• Re-established as a grand duchy	1815
Preceded by Succeeded by County of Oldenburg First French Empire Grand Duchy of Oldenburg
Today part of	Germany

The Duchy of Oldenburg (German: Herzogtum Oldenburg), named for its capital, the town of Oldenburg, was a state in the north-west of present-day Germany. The counts of Oldenburg died out in 1667, after which it became a duchy until 1810, when it was annexed by the First French Empire. It was located near the mouth of the River Weser.

When the main lineage of the House of Oldenburg died out in 1667 with Anthony Günther, Count of Oldenburg, it fell to the Frederick III of Denmark of the line of the Dukes of Holstein-Gottorp, who married Grand Duchess Anna Petrovna of Russia, daughter of Peter the Great. Another, his first cousin, Frederick August I, became Duke of Oldenburg in 1774. One of his brothers, Adolf Frederick, became King of Sweden. Another brother, Prince Georg Ludwig of Holstein-Gottorp, was father of Peter I, who became Grand Duke of Oldenburg in 1823. All subsequent Rulers of Oldenburg were his descendants.

Its ruling family, the House of Oldenburg, also came to rule in Denmark, Norway, Sweden, Greece and Russia.^[1] The heir of a junior line of the Greek branch, through Prince Philip, Duke of Edinburgh, hold the thrones of the United Kingdom and the other Commonwealth realms after the passing of Queen Elizabeth II.