Which European capital is the seat of the world’s only surviving sovereign grand duchy?

Luxembourg City is the seat of the world’s only surviving sovereign grand duchy, Luxembourg.

A grand duchy is a state ruled by a grand duke or grand duchess. Luxembourg became a grand duchy in 1815 through the arrangements of the Congress of Vienna, and it remains a sovereign constitutional monarchy. The monarch’s official title is Grand Duke of Luxembourg.

Luxembourg City is the country’s capital and the location of major state institutions, including the Grand Ducal Palace and the Chamber of Deputies. The country’s political system combines a hereditary head of state with parliamentary government.

The title can cause confusion because several European states are monarchies, but Luxembourg is the only independent sovereign state that retains the rank of grand duchy. Liechtenstein is a principality, Monaco is a principality, and the Netherlands and Belgium are kingdoms.