According to Wagner's housekeeper, Anna Mrazek, "it was easy to tell that something was going on between Frau Cosima and Richard Wagner". Mrazek said that later in the visit von Bülow found his wife in Wagner's bedroom, but nevertheless made no demands for an explanation, either from Wagner or from his wife. Nine months after this visit, on 10 April 1865, Cosima gave birth to a daughter, Isolde. Such was von Bülow's devotion to Wagner that he accepted the child as his own, and registered her as "the legitimate daughter" of Hans and Cosima von Bülow. Wagner attended the Catholic baptism on 24 April. On 10 June 1865, at the Munich Hofoper, von Bülow conducted the premiere of Wagner's "Tristan und Isolde". Wagner's role at Ludwig's court became controversial; in particular, Ludwig's habit of referring Wagner's policy ideas to his ministers alarmed the court. When Wagner demanded the sacking both of Ludwig's cabinet secretary and of his prime minister, there was a public outcry, and in December 1865 Ludwig reluctantly told Wagner to leave Bavaria. The king did not, however, withdraw his patronage or financial support. After a few months' wandering, in March 1866 Wagner arrived in Geneva, where Cosima joined him. They travelled together to Lucerne where they found a large lakeside house, the Villa Tribschen. Wagner made immediate arrangements to rent the house, at the king's expense, and by 15 April was installed in his new home. Immediately upon signing the lease, Wagner invited the von Bülows and their children to stay with him. They spent the summer there, returning briefly to Munich before von Bülow left for Basel while Cosima went back to Tribschen. By now von Bülow understood his wife's relationship with Wagner; he wrote to a friend that "since February 1865 I was in absolutely no doubt about the extremely peculiar nature of the situation". Wagner, anxious to avoid associating Cosima in a public scandal, deceived Ludwig into issuing a statement in June 1866 which declared the unbroken sanctity of the von Bülows' marriage, and promised retribution for those daring to suggest otherwise. By this time Cosima was pregnant with her second child by Wagner; a daughter, Eva, was born at Tribschen on 17 February 1867. Through all this, von Bülow retained his devotion to Wagner's music.