From "Royalty Digest" magazine and their report on the Spanish wedding: "A family dinner was served at Zarzuela Palace attended by some 45 Royal guests and close relations. Upon leaving, Prince Victor Emanuele threw two strong blows of his fists at his cousin Duke Amedeo of Aosta who, bleeding, had to be supported by Queen Anne Marie, while it is said that poor King Juan Carlos, visibly tired, uttered "never again". "
Other reports added that while Queen Anne Marie was looking after the bleeding Duke, an Arab Prince fetched ice; when the Savoy party were safely outside, Princess Marina Doria, Victor Emanuel's wife, returned to offer profuse apologies.
The incident was alleged to have occurred when Duke Amedeo patted his cousin on the back, in what he thought was a friendly manner. The Prince obviously thought otherwise. An indication of the strained and fraught relations between the two 'rival' branches of the House of Savoy!