The Hanover people began to murmur. The only means they could find of keeping their Prince at home with them was to build a magnificent opera house where spectacles and _fêtes_ resembling those in Venice could be given. The idea was good. Ernest Augustus warmly took up the scheme for his opera house, which, built and decorated by the Italians between 1687 and 1690, was the most beautiful in all Germany.[131] For this opera house Steffani was engaged as Kapellmeister.[132] Agostina Steffani is one of the most curious figures in history.[133] Born in 1653 at Castelfranco, near Venice, of a poor family, after being a choir-boy at St. Mark's, he was taken in 1667 to Munich by the Count of Tattenbach, who had been the pupil of Ercole Bernabei, a master brought up in the purest Roman style.[134] At the same time he had been given a very complete education in literature, science, and theology, for he was destined for the priesthood, and with a view to becoming Abbé.[135] He was appointed organist at the Court, and music-director. Since 1681 a set of his operas, played at Munich (and especially _Servio Tullio_ in 1685[136]), spread his renown through Germany. The Duke of Hanover enticed him to his Court, and in 1689 the new Hanoverian theatre was inaugurated by one of Steffani's operas, for which the Duchess Sophia furnished, it is said, the patriotic subject _Henrico Leoni_.[137] Then followed a set of fifteen operas of which the _mise en scène_ and music had an amazing popularity in Germany.[138] Cousser introduced them at Hamburg as models of true Italian song, and Keiser modelled himself partly on them, ten years before Handel in his turn followed Keiser's pattern. The Opera did not enjoy a long life at Hanover. The Duke alone liked it. The Duchess Sophia had much less sympathy for this kind of art.[139] The ballets and the masquerades put the Opera to shame. Steffani was otherwise occupied with more serious business elsewhere. In the Treaty of Augsburg, Ernest Augustus of Hanover had taken sides with the Emperor. To recompense his fidelity the Emperor bestowed on him the dignity of Prince-Elect, but in the confusion of the Empire it was not easy to clear up the situation. It was necessary to send an Ambassador Extraordinary to the great German Courts. The choice of all fell on Steffani, who, being a Catholic Abbé, could more easily serve as intermediary between the Protestant Court of Hanover and the Catholic Courts;[140] his mission was so well accomplished that in 1697 the Duke of Hanover obtained for him the title of Elector. This astonishing diplomat had found the means of writing operas. After the death of Ernest Augustus in 1698 he gave up opera writing, but continued to occupy himself with politics. He became in 1703 the secret adviser to the Elector Palatine, the President of the Religious Council, who was created a noble. At the same time Pope Innocent II made him in 1706