Opera in German such as opera seria. Some Baroque composers, such as Reinhard Keiser, did try to challenge Italian dominance, and the theatre principal Abel Seyler became an eager promoter of German opera in the 1770s, but it was only with the appearance of Mozart that a lasting tradition of serious German-language opera was established. Mozart took the simple, popular genre of "Singspiel" and turned it into something far more sophisticated. Beethoven followed his example with the idealistic "Fidelio"; and with "Der Freischütz" of 1821, Weber established a uniquely German form of opera under the influence of Romanticism. Weber's innovations were eclipsed by
Italian opera composers of the next generation: Francesco Cavalli and Antonio Cesti. In Polish–Lithuanian Commonwealth a tradition of operatic production began in Warsaw in 1628, with a performance of "Galatea" (composer uncertain), the first Italian opera produced outside Italy. Shortly after this performance, the court produced Francesca Caccini's opera "La liberazione di Ruggiero dall'isola d’Alcina", which she had written for Prince Władysław Vasa three years earlier when he was in Italy. Another first, this is the earliest surviving opera written by a woman. "Gli amori di Aci e Galatea" by Santi Orlandi was also performed in 1628. When Władysław was king (as