Countess of Oldenburg

County of Oldenburg
Grafschaft Oldenburg (de)
1091–1774
Coat of arms
Anthem Heil dir, O Oldenburg ("Hail to thee, O Oldenburg")
Map of the County of Oldenburg in the Lower Rhenish–Westphalian Circle
Capital		Oldenburg
Government		Feudal monarchy
Count of Oldenburg
•	1101–08	Elimar I (first count)
•	1773–74	Frederick August I (last count)
History
•	Created on breakup     of Saxony	1091
•	Personal union with     the Kalmar Union	1448–54
•	Part of Denmark	1667–1773
•	Raised to duchy	1774
Preceded by Succeeded by Duchy of Saxony Prince-Bishopric of Münster Duchy of Oldenburg
Today part of		Germany

The County of Oldenburg was a county of the Holy Roman Empire.

In 1448 Christian I of Denmark (of the House of Oldenburg), Count of Oldenburg became King of Denmark, and later King of Norway and King of Sweden. One of his grandsons, Adolf, Duke of Holstein-Gottorp was the first Duke of Holstein-Gottorp.

When the main lineage of the House of Oldenburg, i.e. Anthony Günther, Count of Oldenburg died in 1667, it fell to the Danish Royal Family. Charles Frederick of the line of the Dukes of Holstein-Gottorp married Grand Duchess Anna Petrovna of Russia, daughter of Peter the Great. 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. Subsequent Rulers of Oldenburg were all his descendants.