An idea of building a stable theatre in Prague might have risen shortly after 1776. Its realization was undertaken by enlightened nobleman and art-lover František Antonín Count Nostic – Rieneck (1725-1794). He was a very outstanding person and he belonged among the favourites of Emperor Joseph II, because he supported his reforms. On the other hand, he was a representative of territorial patriotism and he wished promotion of the Czech Kingdom and Prague. Prague court builder, Antonín Hafenecker was ordered to elaborate the design for the theatre building. The foundations stone for the building was laid on 7th June 1781. The theatre, named Count’s Nostic National Theatre, was ceremoniously opened on 21st April 1783 with Lessing’s tragedy Emilia Gallotti. The original budget was exceeded four times. However, the used efforts and financial means were definitely worth the final result. Prague then achieved one of the most beautiful theatres in Europe. The building of rectangular floor-plan with a saddle roof has a magnificent classicist frontage with pairs of columns and a tympanum. The auditorium had two box rows, a gallery, a parterre and capacity of about 1000 spectators. Artistic decoration of interior got great attention. During life of the theatre numerous performance were played there and many top artists stood on the stage. It became world-famous as the world premiere of Don Giovanni opera took place there on 29th October 1787. The author, musical genius, Wolfgang Amadeus Mozart, composed it for Prague, which he liked very much and Prague citizens loved him as well, and he composed it mostly in Prague. Mozart paid great attention to studying the piece with an orchestra and he conducted the ceremonious premiere as well as the next four repeats.