Who was the architect of the opera house where Thaïs was first performed?
Palais Garnier The Palais Garnier (] French    ) is a 1,979-seat opera house, which was built from 1861 to 1875 for the Paris Opera. It was called the Salle des Capucines, because of its location on the Boulevard des Capucines in the 9th arrondissement of Paris, but soon became known as the Palais Garnier, in recognition of its opulence and its architect, Charles Garnier. The theatre is also often referred to as the Opéra Garnier (French    ) and historically was known as the Opéra de Paris or simply the Opéra, as it was the primary home of the Paris Opera and its associated Paris Opera Ballet until 1989, when the Opéra Bastille opened at the Place de la Bastille. The Paris Opera now mainly uses the Palais Garnier for ballet.
Il Bellerofonte Il Bellerofonte is an 18th-century Italian opera in three acts by the Czech composer Josef Mysliveček. It conforms to the serious type (opera seria) that was typically set in the distant past. The libretto, based on the Greek legend of Bellerophon, was written by Giuseppe Bonecchi. The work was dedicated to King Ferdinand I of the Two Sicilies and was first performed at the Teatro San Carlo in Naples on 20 January 1767, the birthday of his father, King Charles III of Spain. The cast featured two stellar singers of the time, Caterina Gabrielli and Anton Raaff, in the leading roles. The opera was only the composer's second one, and the first that permitted him the opportunity to write music for first-rate vocal artists. The production was highly successful, indeed responsible for a meteoric rise in his reputation as an operatic composer. From the time of the premiere of "Bellerofonte" until his death in 1781, Mysliveček succeeded in having more new "opere serie" brought into production than any other composer in Europe. During the same time span, he also had more new operas staged at the Teatro San Carlo in Naples than any other composer.