This dissertation examines music and text circulation in cosmopolitan Europe during the last decades of the eighteenth century through the lens of translation. London in the late eighteenth and early nineteenth centuries was the largest center of Italian operatic performance outside of Italy. All performances sung at the King’s Theatre, London, were sung in Italian, the presumed language of opera, even when the works had been originated in other languages. This created the need for a culture of translation and adaptation of works from abroad, making them suitable for a London audience partially through the retention of foreignness and partially through domesticating practices. In the 1790s, a period of political tension between Britain and post-Revolution France, four French operas were presented at the King's Theatre in Italian translations attributed to the poet Lorenzo Da Ponte (1749-1838): Gluck's Iphig�nie en Tauride, Gr�try's Z�mire et Azor, Monsigny's La belle Ars�ne, and Sacchini's Arvire et �v�lina. A quintessentially cosmopolitan man who was never stationary for long, Da Ponte served as the house poet for the King’s Theatre in London from 1792 to 1799 and then again from 1801 to 1805. A large portion of Da Ponte’s job at the King’s Theatre involved utilizing his knowledge of languages and of audience taste to adapt and translate preexisting works for the London stage. This historically grounded, theoretically informed, and performance-oriented examination of Da Ponte’s four translations as sung at the King’s Theatre investigates a world in which translation was a necessary part of daily life in cosmopolitan centers as well as an often overlooked but integral aspect of artistic processes in opera houses.