Yitzchok Isaac Krasilschikov
Rabbi Yitzchok Isaac ben Dov Ber Krasilschikov (1888–May 13, 1965), also known as the Gaon of Poltava, was an exceptional Talmudic scholar and author of a monumental commentary on the Jerusalem Talmud. He was one of the last publicly practicing Orthodox rabbis in Communist Russia.
Read more about Yitzchok Isaac Krasilschikov: Early Years, Talmudic Commentaries