Russian baritone (b. 1866; d. 1942), born Vasily Aleksandrovich Ostrovsky (Василий Александрович Островский).
Correspondence with Tchaikovsky
One letter from Tchaikovsky to Vasily Ostrovsky has survived, dating from 1892, and has been translated into English on this website:
8 letters from Vasily Ostrovsky to the composer, dating from around 1888, are preserved in the Klin House-Museum Archive.