A grand duke is a European hereditary title used either by certain monarchs or by members of certain monarchs families. It is a title of sovereign princes ranking between kings and dukes. In status, a grand duke traditionally ranks below an emperor, not equal of King, Grand prince, Archduke and Prince-Archbishop and above a sovereign prince or sovereign duke. The term grand duke as a monarch reigning over an independent state was a later invention to denote either a particularly mighty duke or a monarchy playing an important political, military and/or economic role, but not large enough to be an empire.
The Grand Duke is the Head of State in Luxembourg, as defined by Article 33 of the Constitution. Both within and outside Luxembourgs borders, the Grand Duke is the representative of the countrys identity. The exercise of sovereign powers is entrusted to the Grand Duke, who has a central and essential role in the institutional system, while respecting the principle that the sovereign reigns but does not govern. The Grand Duke has the power to organize and supervise the administrative services and to make appointments to civil and military posts. Finally, to ensure the maintenance of order and security in the country, the Grand Duke commands the armed forces.
