Duchy of Oldenburg

State · 1806–1870 CE · at its largest around 1834 CE

A northwestern German state on the North Sea coast, raised to a grand duchy after 1815, which later joined the German Empire.

On its lands while it lasted

• Oldenburg (c. 1806 CE): Capital of Duchy of Oldenburg (1806–1870).
• Weilburg (c. 1806 CE): Capital of Duchy of Nassau (1806–1816).
• Wiesbaden (c. 1816 CE): Capital of Duchy of Nassau (1816–1865).

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