It was called KÃ nigliches Opernhaus ( Royal Opera House ) , and it opened with a performance of Meyerbeer 's Ein Feldlager in Schlesien . The reconstruction of the building was supervised by architect Carl Ferdinand Langhans , and the KÃ nigliches Opernhaus ( Royal Opera House ) was inaugurated the following autumn by a performance of Meyerbeer 's Ein Feldlager in Schlesien .