Alexander Sergeyevich Dargomyzhsky (February 14, 1813 – January 17, 1869) was a significant Russian composer known for his contributions to 19th-century Russian opera. Born in the village of Troitskoye, near Tula, Russia, into an aristocratic family, Dargomyzhsky moved to Saint Petersburg in 1817, where his father worked as a government official. Despite starting work in the Treasury Department at a young age, Dargomyzhsky pursued his passion for music, receiving private lessons in piano and composition.

His musical journey took a decisive turn in 1833 when he met Mikhail Glinka, who encouraged him to focus on composition. This led to the creation of his first opera, "Esmeralda," based on Victor Hugo's "The Hunchback of Notre-Dame," completed in 1839 and performed in 1847. Dargomyzhsky's subsequent operas included "The Triumph of Bacchus" and "Rusalka," the latter based on a work by Aleksandr Pushkin and produced in 1856.

Dargomyzhsky was known for his innovative approach to operatic expression, particularly through his last opera, "The Stone Guest," which was notable for its use of melodic recitative and was completed posthumously by César Cui and Nikolai Rimsky-Korsakov. Though not a member, he was regarded as an elder statesman by the group of composers known as The Five, who appreciated his progressive ideas.

In addition to operas, Dargomyzhsky composed nearly 100 songs, numerous piano pieces, and orchestral works, including "Finnish Fantasia," "Cossack Dance," and "Baba-Yaga." His works, characterized by realistic and nationalistic elements, influenced Russian composers such as Borodin and Mussorgsky, as well as the more cosmopolitan Tchaikovsky. Despite his contributions, Dargomyzhsky's works are now seldom performed. He died in Saint Petersburg in 1869 at the age of 55.