He became identified early on with the French romantic movement. Among his friends were writers such as Alexandre Dumas, Victor Hugo and Honoré de Balzac. Later, Théophile Gautier would write:
"Hector Berlioz seems to me to form with Hugo and Delacroix, the Trinity of Romantic Art" Berlioz is said to have been innately romantic; experiencing emotions deeply from early childhood. This manifested itself in his weeping at passages of Virgil as a child, and later in a series of love affairs. Several times his affections were unrequited: his love for the Irish Shakespearean actress Harriet Smithson was the inspiration for his Symphonie Fantastique. He eventually married Smithson, and the relationship quickly fell apart. He planned to murder Marie Moke, another of his loves, and then commit suicide, after he heard that she was to marry the piano maker Pleyel. However, Berlioz was residing in Rome at the time under a Prix de Rome scholarship, and she was in Paris. He got as far as Nice (supposedly dressed as a chambermaid!) before giving up the idea.
Berlioz had a keen affection for literature, and many of his best compositions are inspired by literary works. For The Damnation of Faust, Berlioz drew on Goethe's Faust, for Harold in Italy, he drew on Byron's Childe Harold, and for Benvenuto Cellini he drew on Cellini's own autobiography. For Romeo et Juliette he turned to Shakespeare's tragedy of the similar name. For his magnum opus, the monumental opera Les Troyens, Berlioz turned to Virgil's epic poem The Aeneid. For his last opera, the comic opera Béatrice et Bénédict, Berlioz prepared a libretto based loosely on Shakespeare's Much Ado About Nothing.
During his lifetime, Berlioz was more famous as a conductor than a composer; he regularly toured Germany and England where he conducted operas and symphonic music, both his own and music composed by others.
The music of Berlioz enjoyed a revival during the 1960s and 1970s, due in large part to the efforts of British conductor Colin Davis, who recorded his entire oeuvre, bringing a number of Berlioz's lesser-known works to the light. Davis's recording of Les Troyens was the first complete recording of that work. The work, which Berlioz never saw staged in its entirety during his life, is now revived regularly. In addition to Symphonie Fantastique, other works of his currently in the standard orchestral repertoire are his "légende dramatique" La Damnation de Faust and "symphonie dramatique" Romeo et Juliette (both large scale works for mixed voices and orchestra), and the song cycle Les Nuits d'Été (originally for voice and piano, later with an orchestral accompaniment).
While Berlioz is best known as a composer, he was also a prolific writer, and supported himself for many years writing musical criticism. He wrote in a bold, vigorous style, at times imperious and sarcastic. Evenings With the Orchestra (1852) is a scathing satire of provincial musical life in 19th century France. Berlioz's Memoirs (1870) paints a magisterial portrait of the Romantic era through the eyes of one of its chief protagonists.
A pedagogic work, The Treatise on Modern Instrumentation and Orchestration established his reputation as a master of orchestration. The work was closely studied by Mahler and Strauss and served as the foundation for a subsequent textbook by Nikolai Rimsky-Korsakov who as a music student attended the concerts Berlioz conducted in Moscow and St Petersburg. "Before the visits of Berlioz," wrote music critic Norman Lebrecht there was no Russian music. His was the paradigm that inspired the genre. Tchaikovsky raided the Symphonie Fantastique like a tuck-shop for his third symphony. Mussorgsky died with a copy of the Berlioz Treatise on his bed.
Hector Berlioz is buried in the Cimetiere de Montmartre with his two wives, Harriet Smithson (died 1854) and Marie Recio (died 1862). In 2003, the bicentennary of his birth, a proposal was made to remove his remains to the Panthéon but it was blocked by President Jacques Chirac in a political dispute over Berlioz's worthiness as a symbol of the glory of France in comparison as such figures as Andre Malraux, Jean Jaures and Alexandre Dumas. In his land of birth, Berlioz's still remains something of the neglected prophet.