Great was the interest among Vivaldians and opera-lovers when a score of a large portion of Vivaldi''s lost opera Motezuma (1733) was unexpectedly discovered among manuscripts from the Sing-Akademie zu Berlin returned to Berlin from Kiev in 2000. The find was providential, since in recent decades practically all of Vivaldi''s performable operatic music has been presented to the public. The newly discovered work has thus given a much-needed fillip to everyone concerned with Vivaldi''s operas. Scholarly discussion was initiated in an international symposium held at the De Doelen concert hall in Rotterdam in June 2005 alongside the work''s first modern performance. From the start, it was planned that the papers read at the symposium, augmented by essays commissioned from other scholars, would be gathered into a book centring on Motezuma. The starting point for the contributions, all of which appear in English, is Steffen Voss''s ''Vivaldi''s Music for the Opera Motezuma, RV 723''. This focuses on the opera itself: its origins, transmission, dramaturgy and music. Reinhard Strohm follows with ''Vivaldi and His Operas, 1730-1734: A Critical Survey'': a chronicle of Vivaldi''s operatic activities during the creative period surrounding Motezuma. Strohm''s essay enables one to identify more clearly what is typical - for Vivaldi and for its period - in Motezuma, and what is less typical. Micky White and Michael Talbot then offer a sidelight on Venetian opera from the same period by charting the chequered career of a nephew of Vivaldi in ''Pietro Mauro, detto ''il Vivaldi'': Failed Tenor, Failed Impresario, Failed Husband, Acclaimed Copyist''. Briefly, during the late 1730s, Mauro''s career in opera mirrored Vivaldi''s own at a humbler level, and a scandal in which the former became embroiled may even have had repercussions for his uncle. We move next to the world of librettos and dramaturgy. The ''American'' dimension of the opera is explored in Jurgen Maehder''s ''Alvise Giusti''s Libretto Motezuma and the Conquest of Mexico in Eighteenth-Century Italian Opera Seria''. To choose an American subject for an opera seria was a novelty at the time, and the libretto for Motezuma casts an interesting light on contemporary attitudes towards the Conquista and towards the indigenous civilizations that it brought to a brutal end. Carlo Vitali''s essay ''A Case of Historical Revisionism in the Theatre: Some Undeclared Sources for Vivaldi''s Motezuma'' probes more deeply into the libretto''s historical antecedents. Melania Bucciarelli, in ''Taming the exotic: Vivaldi''s Armida al campo d''Egitto'', explores the treatment of an Ottoman theme in a Vivaldi opera of the period leading up to Motezuma. In a sense, the Ottoman empire formed a prototype of ''alterity'' on which later operatic depictions of non-European peoples could draw, while also supplying a test-bed for the treatment of topical subjects during a tense period of intermittent warfare with the Sublime Porte. The next two contributions redirect the focus towards the music of Motezuma. Kurt Markstrom, in ''The Vivaldi-Vinci Interconnections, 1724-26 and beyond: Implications for the Late Style of Vivaldi'', considers the interaction in the operatic arena between Vivaldi and his brilliant contemporary Leonardo Vinci, who briefly burst on to the Venetian scene in the 1720s before his premature death in 1730 robbed the all-conquering Neapolitan style of one of its heroes. Markstrom shows how Vivaldi was both influenced by, and an influence on, Vinci. Michael Talbot''s essay ''Vivaldi''s ''Late'' Style: Final Fruition or Terminal Decline?'' ponders whether there is any objective basis in positing a ''late'' style in Vivaldi''s case and, if so, where its boundaries lie. His conclusion is that there is indeed a late style, beginning in the second half of the 1720s and divisible into two sub-periods, with Motezuma close to the end of the first. ''Final fruition'' is an apt description of the first sub-period, ''terminal decline'' (with qualifications) of the second. Fittingly, the concluding essay, Frederic Delamea''s ''Vivaldi in scena: Thoughts on The Revival of Vivaldi''s Operas'', confronts the world of present-day staged performance. Why, this author asks, do we commonly pay such respect to notions of historical fidelity in the musical realization of the operas, while we trample so brutally on authenticity in the matter of stagecraft and production. This essay promises to become a seminal text for an ongoing debate.