Category:Dukes of Oldenburg

The title Duke of Oldenburg and the use of the style "Highness" or "Royal Highness" has generally been restricted to the following persons:
 * the ruler of the Duchy of Oldenburg before 1829
 * the head of the Grand Ducal House of Oldenburg after the German Revolution
 * the legitimate sons of a head of the Grand Ducal House of Oldenburg
 * the legitimate male-line descendants of a head of the Grand Ducal House of Oldenburg