Diplomat and operatic impresario. Bom of a noble family in Genoa, he was made ambassador to Vienna in 1749; by 1754 he was in charge of the imperial theaters. In his position as Generalspektakeldirektor he improved the standards both at the Burgtheater and at the Kärntnertortheater. He was a key figure in the Gluckian reform of opera, as he was largely responsible for bringing together Calzabigi and Gluck in 1761 for their epoch-making operatic collaborations. He is also credited with fostering comic opera in Vienna, employing composers such as Giuseppe Scarlatti and Florian Leopold Gassmann to compose opere buffe. In 1764 he resigned from his Viennese posts amid conflict and intrigue. Shortly afterward he was appointed Viennese ambassador to Venice, a post he held until 1784.