The hard and long road of the Teatro dell’Opera di Roma from its opening to nowadays prestigious status is the result of the tenaciousness of its founding father, the building contractor Domenico Costanzi. In 1879 he commissioned the construction to the Milanese architect Achille Sfondrini specialized in theatres. He gave precedence to the acoustics designing a horseshoe shape, conceived as a resonance chamber, three tiers of boxes, an amphitheatre and a gallery to hold up to 2212 spectators. This was surmounted by a dome with frescoes by Annibale Brugnoli. Completed in only eighteen months, the Teatro Costanzi was inaugurated on 27 November 1880 with Semiramide by Rossini, in the presence of King Umberto I and Queen Margherita. The programming went on thanks to the economic and organizational effort of Costanzi himself and later to his son. The theatre saw premieres of operas which became benchmarks of the repertoire all over the world, two of the most memorable were Cavalleria rusticana by Mascagni (1890), and Tosca by Puccini (1900). From 1907 the theatre was run by the impresario Walter Mocchi. In 1912 he entrusted the direction to his wife, the soprano Emilia Carelli. Thus the “Impresa Costanzi” was born. Under the attentive control of Madame Carelli, the theatre became the source of many novelties (Puccini’s La fanciulla del West, Turandot, and Il Trittico, Wagner’s Parsifal, Saint-Saëns’ Samon et Dalila, and the legendary Diaghilev’s Ballet Russes). In 1926 Mussolini requested the City of Rome to purchase the Costanzi, that became the “Teatro Reale dell’Opera”. After this change the architect Marcello Piacentini moved the theatre’s entrance to the side of the square, which was later named after the great tenor Beniamino Gigli, to create extra space for the large public. The interior was enhanced with new decorations and the majestic chandelier with its twenty-seven thousand crystal drops; it has illuminated the orchestra stalls since 27 February 1928, the day of its second inauguration with Nerone by Boito. In 1946 with the birth of the Italian Republic, the theatre became officially the “Teatro dell’Opera di Roma”. In 1958, in preparation for the 1960 Olympics, Piacentini gave the Theatre the appearance we can still admire today further with definitive renovations. 150 years of successes involved the greatest voices, conductors, and musicians. Mascagni, Puccini, and Respighi have bestowed upon it an honourable place in Italian operatic history as the cradle of verismo and twentieth century opera.