Leo Nicholaievich Tolstoy was a Russian writer and philosopher, best known for his novels "War and Peace" and "Anna Karenina." He is considered one of the greatest novelists of all time and his works often explore themes of morality, spirituality, and the human experience. Tolstoy was also a prominent thinker and advocate for nonviolent resistance and social justice. His writings have had a profound impact on literature and continue to be widely studied and admired around the world.