Otto von Habsburg was the last crown prince of Austria-Hungary from 1916 until the dissolution of the empire in November 1918. In 1922, he became the pretender to the former thrones, head of the House of Habsburg-Lorraine, and sovereign of the Order of the Golden Fleece upon the death of his father. He resigned as Sovereign of the Golden Fleece in 2000 and as head of the Imperial House in 2007.

The House of Habsburg-Lorraine originated from the marriage in 1736 of Francis III, Duke of Lorraine and Bar, and Maria Theresa of Austria, later successively Queen of Bohemia, Queen of Hungary, Queen of Croatia and Archduchess of Austria. Its members are the legitimate surviving line of both the House of Habsburg and the House of Lorraine and inherit their patrimonial possessions from their female line of the House of Habsburg and from the male line of the House of Lorraine.