Although Vivaldi is now best known for his many instrumental works, he was also a prolific composer of operas. By the time of his operatic debut in 1713, at the age of thirty-five, he had already achieved an international reputation as a concerto composer; from then on both activities continued in parallel for the rest of his career. We do not know exactly how many operas Vivaldi wrote: a letter of 1739 claims ninety-four, but this figure, reflecting Vivaldi’s penchant for exaggeration, doubtless included revivals and rearrangements of his own and other composers’ works. Nevertheless, we have over fifty surviving printed librettos and around twenty scores, most of which are largely complete. Vivaldi’s involvement with the operatic scene was not only as a composer: he was active throughout his career as impresario, running theatres, booking singers (often knocking down their fees in the process!), and putting on works by other composers as well as his own. In fact it was his operatic engagements that led to many of his travels outside Venice, to centres as far afield as Rome, Florence, Vienna and probably Prague.