Question: Wilhelm von Lenz, was a Baltic German Russian official and writer, and was a friend of many mid-century Romantic composers, including Hector Berlioz, that died on which date, was a French Romantic composer, best known for his compositions "Symphonie fantastique" and "Grande messe des morts" (Requiem)?
Related documents: [0]  [DOC] Wilhelm von Lenz (born 20 May 1809 in Riga - died 7 January 1883 in Saint Petersburg) was a Baltic German Russian official and writer. Wilhelm von Lenz was a friend of many mid-century Romantic composers, including Franz Liszt, Frédéric Chopin and Hector Berlioz, Lenz's most important and influential work was an early biography of the German composer Ludwig van Beethoven, entitled "Beethoven et ses trois styles" (1855), written in response to the disparagement of Beethoven by Alexander Ulybyshev in his "Nouvelle biographie de Mozart" (1843). Lenz promoted the idea (already suggested by earlier figures such as François-Joseph Fétis) that Beethoven's musical style be divided into three characteristic periods. Lenz's periodisation, with minor changes, is still widely used today by musicologists in discussing Beethoven's compositions. [END] 
[1]  [DOC] Louis-Hector Berlioz (] (English: ); 11 December 1803 – 8 March 1869) was a French Romantic composer, best known for his compositions "Symphonie fantastique" and "Grande messe des morts" (Requiem). Berlioz made significant contributions to the modern orchestra with his "Treatise on Instrumentation". He specified huge orchestral forces for some of his works, and conducted several concerts with more than 1,000 musicians. He also composed around 50 songs. His influence was critical for the further development of Romanticism, especially in composers like Richard Wagner, Nikolai Rimsky-Korsakov, Franz Liszt, Richard Strauss, and Gustav Mahler. [END] 
Answer: 
8 March 1869
8 March 1869