A Russian composer of French descent, Georgy L'vovich Catoire (also often spelled "Katuar") (1861-1926) is one of the most neglected composers of the turn of the nineteenth and twentieth centuries. Catoire composed a number of piano pieces, most of which are chamber and solo works. These pieces are rarely studied or performed in the West. This study makes an attempt to fill this void. It thoroughly investigates Catoire's life, as well as looks into his genealogy, since his family was influential in commercial, political and cultural life of Russia for more than a hundred years. It also discusses his works for piano, with particular emphasis on Poem, Second Sonata for Violin and Piano, Op. 20. This sonata exemplifies the composer's mature style, characterized by the refinement of the harmonic and rhythmical ideas, while demonstrating melodious ingenuity and clear structural form. To date, there is no known study on this subject of such scope both in Russian and in English languages.