Hans von Bülow
In 1864 he became the Hofkapellmeister in Munich.  This was a very important conducting job and it made him extremely famous.  He conducted the first performances of two Wagner operas: Tristan und Isolde (1865) and Die Meistersinger von Nürnberg (1868).  These were extremely successful.  Meanwhile Cosima was having a love affair with Richard Wagner.  In 1868 she left her husband to live with Wagner, taking their daughters with her.  She divorced  Bülow, who went to Florence for a while to recover from the shock.  However, he always continued to show great respect for Wagner and continued to conduct his music.  When Wagner died in 1883 he was terribly sad.