Boson of Arles and Adoption
Also known as Boso
Duke of Arles and King of Provence
Boson was born before 850, the son of Buwin, Count of Ardennes. His father made him governor of Lombardy and in 879 Boson convened the nobility of Provence and had himself elected King of Provence. He was the brother-in-law of Charles the Bald and was the favorite of Pope John VIII to succeed Charles as Holy Roman Emperor. This was apparently made public by a ceremony called "adoption by hair," in which Boson cut off his own hair and gave it to the Pope, signifying his acceptance of his adoption. It was a kind of formal adult adoption, where the Pope made his choice public, akin to the adoptions in classical Rome to secure the succession, and also to that of Jean-Baptiste Bernadotte, which made him heir to King Karl XIII of Sweden and Norway (Karl XIV Johan).
The Catholic Encyclopedia Brewer, E. Cobham. Dictionary of Phrase and Fable. New and enlarged edition. (1894) ("Adoption by hair"). Also available at: www.bibliomania.com/Reference/PhraseAndFable/data/15.html