The fascinating phenomenon of the migration of theatrical subjects between literary genres, languages and countries is enriched through a new example discussed in this article. A handwritten libretto compiled in Rome for the court of Vienna, La simpatia nell'odio, overo Le amazoni amanti by Giovanni Pietro Monesio (1664), was discovered to be a faithful translation of the Spanish play Las Amazonas by Antonio de Solís (1657), hitherto known as the basis of a much later libretto, Caduta del regno delle Amazzoni, by Domenico De Totis (1690), set by Bernardo Pasquini. Monesio's libretto not only allows us to reconstruct the manner and time of the European circulation of a Spanish subject (from Madrid to Rome, to Vienna and Naples), but also to shed light on wider cultural aspects. First of all, it increases the number of librettos closely based on Spanish plays, of which so far only a few examples by Giulio Rospigliosi were known. Secondly, it provides further proof of the hypotheticised Spanish influence on the fortune of the Amazons in Italian opera and confirmation that its first appearance was beyond the Alps rather than in Italy. Finally, in the context of the the Habsburg Viennese court, the success of the Amazons seems to be linked to the political need to create a strong symbolic association between the ‘discourse’ on the virago and the legitimation of female power.