Wilhelm Karl Friedrich Fitzenhagen was a German cellist, composer and instructor, best known today as the dedicatee of Pyotr Ilyich Tchaikovsky's Variations on a Rococo Theme. Fitzenhagen was born in Seesen in the Duchy of Brunswick, where his father served as music director. Beginning at age five, he received lessons on the piano, the cello and the violin. Many times, he had to substitute for wind players absent due to various emergencies. At 14, Fitzenhagen began advanced study of the cello with Theodore Müller. Three years later Fitzenhagen played for the Duke of Brunswick, who released him from all military service. In 1867 some noble patrons enabled him to study for a year with Friedrich Grützmacher in Dresden, A year later he was appointed to the Dresden Hofkapelle, where he started his career as soloist. Fitzenhagen's playing at the 1870 Beethoven Festival in Weimar attracted the attention of Franz Liszt, who had formerly served as music director there. Liszt attempted to talk Fitzenhagen into joining the court orchestra. Fitzenhagen, however, had already accepted a professorship at the Moscow Conservatory. Fitzenhagen became regarded as the premier cello instructor in Russia and equally well known as a soloist and chamber music performer. He was appointed solo cellist to the Russian Musical Society and director of the Moscow Music and Orchestral Union. It was through this union that he made many concert appearances as a soloist. He formed a friendship with Tchaikovsky, giving the first performances of all three of that composer's string quartets as well as the Piano Trio as a member of the Russian Music Society's quartet. Fitzenhagen trained a number of excellent cellists, including Joseph Adamowski, who went to America in 1889 to join the newly formed Boston Symphony Orchestra and helped found the orchestra's pension program. Adamowski also formed a string quartet named after him and taught at the New England Conservatory in Boston. Fitzenhagen died in Moscow.