Grand duke

The title of grand duke, limited almost exlusively to Slavic and Germanic countries,, is ranked in honour below kings but higher than sovereign princes. The title of grand duke is currently used by the male sovereigns of Luxemburg. Previously, the it was also given to the head of the then autonomous region of Finland (prior to 1917) and to rulers of some states within the Holy Roman Empire.

The nation or territory ruled by a grand duke is called a grand duchy; the feminine form is grand duchess.

The term probably originated from Germany, where it was used to refer to the rulers of medieval Russian states.

Grand Duke is also the translated title given to sons and grandsons of the tsars of Russia, whether living or dead. A more accurate translation of the Russian title would be Great Prince - especially in the pre-Petrine era - but the term is not standard nor widely used. This title was not given to consorts of a daughter or granddaughter of a tsar.

Finally, Grand Duke is the translated form of the title megadoukas , infrequently used in the Byzantine Empire during the Paleologus dynasty.