In 1864 he became the Hofkapellmeister in Munich, and it was at this post he achieved his principal renown. He conducted the premieres of two Wagner operas, Tristan und Isolde and Die Meistersinger von Nürnberg, in 1865 and 1868 respectively; both were immensely successful. Meanwhile, however, Cosima had been carrying on an affair with Richard Wagner and gave birth to their daughter Isolde in 1865. Two years later, they had another daughter, Eva. Although Cosima and Wagner's affair was now open knowledge, Bülow still refused to grant his wife a divorce. It was only when she gave birth to a third child, Siegfried, that the conductor at last relented. Their divorce was finalized in 1870, after which Cosima and Wagner married. Bülow never spoke to Wagner again, and he did not see his former wife for 11 years afterwards. However, he apparently continued to respect the composer on a professional level, as he still conducted his works and mourned Wagner's death in 1883. In July 1882 he married the actress Marie Schanzer.