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)?
Sentence (from "Hector Berlioz"): 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).
Relevant evidence: Yes