Pio Siotto
He made a tryptich of sardonyx cameos to celebrate the family of the Queen Margherita of Savoy: the first depicts the monument raised in Turin for the Prince Ferdinand , Duke of Genoa ( Queen's father ) , the other an equestrian statue of King Victor Emmanuel II of Italy , father of the then present king; and the third medal was the portrait of the then Prince of Naples , later King Victor Emmanuel III of Italy . 
<triplet> Margherita of Savoy <subj> Prince Ferdinand, Duke of Genoa <obj> father <triplet> Victor Emmanuel II of Italy <subj> Prince Ferdinand, Duke of Genoa <obj> sibling