Graz Opera is an Austrian opera house and opera company based in Graz. The orchestra of the opera house also performs concerts as the Graz Philharmonic Orchestra. The opera had been performed in Graz since the 17th century, originally in a former coach house on the royal estates of the Habsburgs. The National Theater (Schauspielhaus Graz), built in 1776, has seen many premieres of Mozart's works, although today (after many reconstructions) it is dedicated to plays. The first dedicated opera house in the city and the immediate predecessor of the Graz Opera was the Thalia Theater, adapted in 1864 from an old circus hall. Plans for a new theater suited to the city's growing size and importance and intended to be a "new home for German art" were first proposed in 1887. Designed by Ferdinand Fellner and Herman Helmer in a neo- Baroque, the Graz Opera opened in 1899 with a performance of Schiller's play William Tell, followed a few days later by Wagner's opera Lohengrin.