Cesar Cui(1835-1918), Russian composer and critic, one of "The Mighty Five", he received his early music education with Moniuszko in Poland. He attended Engineering School in St. Petersburg and became a professor, but he befriended with all the members of "The Mighty" and concentrated in music. He started to compose operas or in collaboration with Rimsky-Korsakov, Borodin, Mussorgsky, and Minkus. He composed operas, orchestral and chamber music, 24 pieces for violin and piano.
Photo of this stamp is Cui, but name is missprinted as Rimsky-Korsakov