Prince of Orange

Prince of Orange is a title originally associated with the sovereign Principality of Orange, in what is now southern France. Under the Treaty of Utrecht of 1713, Frederick William I of Prussia ceded the Principality of Orange to King Louis XIV of France (while retaining the title as part of his dynastic titulature). After William III of England died without children, a dispute arose between Johan Willem Friso and Frederick I of Prussia, which was settled in the Treaty of Partition (1732); consequently, Friso's son, William IV had to share use of the title "Prince of Orange" (which had accumulated prestige in the Netherlands and throughout the Protestant world) with Frederick William I of Prussia. The title is traditionally borne by the heir apparent of the Dutch monarch. The title descends via absolute primogeniture since 1983, meaning that its holder can be either Prince or Princess of Orange.

The Dutch royal dynasty, the House of Orange-Nassau, is not the only family to claim the title. Rival claims to the title have been made by German emperors and kings of the House of Hohenzollern and by the head of the French noble family of Mailly. The current users of the title are Catharina-Amalia, Princess of Orange suo jure (Orange-Nassau), Georg Friedrich, Prince of Prussia (Hohenzollern), and Guy, Marquis de Mailly-Nesle (Mailly).