The extraordinary correspondence between the impresario Felice Giardini and his friend Gabriele Leone lies at the centre of this study of Italian opera in London in the eighteenth century. Hired by Giardini in 1763 to engage Italian performers for a season of opera and ballet at The King's Theatre, Leone was sued by the impresario when the performers he had recruited proved to be second rate. His response was to publish the letters and instructions that Giardini had sent to him, which feature the impresario's ten commandments for the novice foreign opera agent. These letters are transcribed and translated in this volume. As the authors reveal, the documents provide a vivid and detailed source of information about the world of eighteenth-century Italian opera, both in London and in Italy.