Which composer was the son-in-law of Franz Liszt?

On 25th August 1870, Richard Wagner married Francesca Gaetana Cosima Liszt, the illegitimate child of Franz Liszt. Wagner (1813-1883) was a German opera composer and friend of the Hungarian composer, Liszt (1811-1886), who did not initially approve of Wagner's marriage to his daughter. Since Cosima was pregnant with Wagner's child, Liszt allowed the wedding to go ahead.

Wagner was one of the most important opera composers in Germany during his lifetime. He composed ten operas, most of which are based on stories from German mythology. As well as the music, Wagner always wrote the libretto (words). Wagner also chose the singers for his operas and composed the music in such a way to prevent the audience from applauding after each major solo.

Wagner's popular operas include 'Tannhäuser', based on the story of the legend of a poet of the same name; 'Lohengrin', about a character from Arthurian legend; and 'Tristan und Isolde' (Tristan and Isolde), a tragic love story. Following Wagner's death, his wife devoted her life to promoting his work.

Liszt was one of the greatest pianists and wrote a lot of music for the piano. Some say his piano pieces were harder to play than anything that had been written before. Liszt predominately wrote short studies but also completed a piano sonata and two piano concertos.