In 1808, Spohr practiced with Beethoven at the latter's home, working on the Piano Trio, Op. 70 No. 1, "The Ghost". Spohr wrote that the piano was out of tune and that Beethoven's playing was harsh or careless. In 1812, Spohr conducted a concert in the of the French-occupied Principality of Erfurt to celebrate Napoleon's 43rd birthday. Spohr later worked as conductor at the Theater an der Wien, Vienna (1813–1815), where he continued to be on friendly terms with Beethoven; subsequently he was opera director at Frankfurt (1817–1819) where he was able to stage his own operas — the first of which, "Faust", had been rejected in Vienna. Spohr's longest period of employment, from 1822 until his death in Kassel, was as the director of music at the recently succeeded William II, Elector of Hesse's court of Kassel, a position offered him on the suggestion of Carl Maria von Weber. In Kassel on 3 January 1836, he married his second wife, the 29-year-old Marianne Pfeiffer. She survived him by many years, living until 1892.