Modest Petrovitch Mussorgsky was born in Karevo, Russia in 1839, of an aristocratic family. He played a piano concerto by John Field in front of an audience when he was only 9 years old. (John Field was an Irish-born composer who had settled in Moscow). He went to St Petersburg, where he became an officer in the army, but left 6 years later to dedicate himself to composition.
He became one of a group of five friends, all composers, who helped and encouraged each other. These were Cui, Rimsky-Korsakov, Borodin, and Balakirev, and together they founded the Russian Nationalist school. Famous works by him include Night on the Bare Mountain, the Opera Boris Godunov, and a suite of piano pieces called Pictures at an Exhibition. This suite was orchestrated by Ravel later, and it is most often heard in this form today.
In later years Mussorgsky became poor, relied on a circle of drinking companions for food and housing, and started drinking heavily himself, becoming an alcoholic. He died in 1881 as a result of his alcoholism.