text: The years 1747 and 1748 brought Gluck two highly prestigious engagements. First came a commission to produce an opera for Pillnitz, performed by Pietro Mingotti's troupe, to celebrate a royal double wedding that would unite the ruling families of Bavaria and Saxony. Le nozze d'Ercole e d'Ebe, a festa teatrale, borrowed heavily from earlier works, and even from Gluck's teacher Sammartini. The success of this work brought Gluck to the attention of the Viennese court, and, ahead of such a figure as Johann Adolph Hasse, he was selected to set Metastasio's La Semiramide riconosciuta to celebrate Maria Theresa's birthday. Vittoria Tesi took the title role. On this occasion Gluck's music was completely original, but the displeasure of the court poet, Metastasio, who called the opera "archvandalian music", probably explains why Gluck did not remain long in Vienna despite the work's enormous popular success (it was performed 27 times to great acclaim). For the remainder of 1748 and 1749 Gluck travelled with Mingotti's troupe, contracting a venereal disease from the prima donna and composing the opera La contesa de' numi for the court at Copenhagen, where he repeated his concert on the glassharmonica.
  In 1750 he abandoned Mingotti's group for another company established by a former member of the Mingotti troupe, Giovanni Battista Locatelli. The main effect of this was that Gluck returned to Prague on a more consistent basis. For the Prague Carnival of 1750 Gluck composed a new opera, Ezio (again set to one of Metastasio's works, with the manuscript located at the Lobkowicz Palace). His Ipermestra was also performed in the same year. The other major event of Gluck's stay in Prague was, on 15 September 1750, his marriage to Maria Anna Bergin, aged 18 years old, the daughter of a rich (but long-dead) Viennese merchant. Gluck seems to have spent most of 1751 commuting between Prague and Vienna.