Hector Berlioz was a French composer of the Romantic era. He was born in 1803 and is best known for his Symphonie Fantastique, which was composed in 1830. He also wrote operas, choral works, and orchestral pieces. Berlioz was a pioneer in the use of large orchestras and was one of the first composers to use a full-sized orchestra. He was also an innovator in the use of musical form and instrumentation.