Ciro riconosciuto was written in Vienna for the birthday of Empress Elizabeth and performed, with music by Antonio Caldara, in the garden of the imperial summer residence (the Favorita) on 28 August 1736. Although not one of Metastasio’s most popular works, after the premiere the libretto was set for several Italian theatres. The subject and plot structure shared with Metastasio’s dramas its descent from ancient sources and successful dramatisations, showcasing Metastasio’s literary ambitions.

To discuss the libretto of Ciro riconosciuto in relation to its sources and to Metastasio’s reflections on poetics, recorded in his most important treatise Estratto dell’ Arte Poetica d’ Aristotile e osservazioni sulla medesima, is a historiographical imperative, as well as a helpful approach to appreciating Metastasio’s output. The assessment of how themes or strategies employed by spoken theatre were translated into eighteenth-century librettos and their settings has been coming into focus since the late 1970s, in no small measure through the studies of Reinhard Strohm. The result has been a definition of musical dramaturgy which provides insight into the complex relationship between opera, contemporary theatrical practice and literary genres. As a dramaturgical structure, dramma per musica began to be influenced by spoken tragedy during the last decade of the seventeenth century. Librettists never entirely subscribed, however, to tragedy’s precepts, as comparisons between Metastasian librettos and their dramatic models show. The primary components or codes of the classical tradition (subject, characters, affections, poetry, scenic types, etc.) were nonetheless retained – to the extent that, according to contemporary observers, Metastasio’s librettos were performed without music – while the actual changes in structure were intended to strengthen some plot lines or motifs. Other modifications, on the contrary, preserved the conventions of the operatic genre, such as the three-act structure, the reduced number of characters, loose application of the unity of place, a lieto fine (mostly with a repenting villain), arias and choruses.