Pierre is 20 when the story begins, and he is the illegitimate son of a rich count. He is a massive man, and his weight is a reflection of his continual struggle for self-control: he has prodigious appetites for food, drink, and women. The other side of Pierre is that he is a thoughtful and philosophical man who is searching for truth and wishes to discover how to lead a meaningful life. Pierre unexpectedly inherits his father's millions because Anna Mikhailovna schemes to help him, and he is taken up by society as a result. People take advantage of him, and he is easily persuaded to part with his money. His best friend is Andrei Bolkonsky, who loves him for his kind and generous nature. Pierre has a bad first marriage but ultimately winds up with the heroine of the story, Natasha. As a result of his experiences as a prisoner of war and his contact with a wise peasant, Pierre finally learns to live in the now, which imbues his life with all its necessary meaning.
Prince Andrei is the secondary hero of the story, a handsome, brooding intellectual, both a romantic and an idealist—but he covers that up with an analytical façade. Andrei is about 27 at the beginning of the story, married to a beautiful aristocrat whom he despises because she is shallow. He is disgusted with aristocratic society and its pretentions and thus decides to enlist in the war against France. Andrei is also a seeker of truth, like his best friend Pierre, although he is more cynical and pessimistic. Andrei fights at Austerlitz and learns that he craves glory and wants to be known; he also has a spiritual awakening after he is wounded that gives him a larger perspective on war. Andrei's wife dies, and he later falls deeply in love with Natasha—a woman who breaks his heart. He dies from a second wound received in the Battle of Borodino.
Natasha is the primary heroine of the novel. She is the quintessential Russian woman, meaning she has all the traits the author associates with the strength and beauty of his homeland. Natasha is alluring to everyone, especially men, because she is so full of life and reflects a joyfulness and spontaneity that is contagious. However this spontaneity also causes her to act rashly and without regard for consequences. Natasha has several crushes in the novel but falls in love with Andrei and accepts his proposal of marriage. However the spontaneous aspect of her nature, which propels her to follow her emotions without forethought, leads her to succumb to the seduction of Anatole. She agrees to elope with him, although their plans are foiled, and the seduction is not completed. Natasha reunites with Andrei when he is wounded the second time and cares for him until he dies. At the end of the novel, she marries Pierre and becomes a much calmer person, focused on her husband and children.
Nikolai Rostov is the brother of Natasha and the eldest child of the Rostov clan. He is a man of action who wants to prove himself in the military without any help from his family. Nikolai fights in both wars against the French and receives several promotions as he becomes a battle-tested warrior. Occasionally he is forced by circumstances to question the morality of what he does because he is essentially a deeply moral man. Nikolai has initially promised himself to Sonya, but he loves her like a sister and also needs to marry someone who can help him restore the family fortune. Nikolai falls in love with Princess Marya and marries her, and he learns from his father's mistakes when it comes to managing land and money.
Princess Marya is deeply spiritual, like her brother Andrei, although her spirituality is grounded in the Russian Orthodox faith. She is the long-suffering companion and caretaker of her difficult and exacting father, Prince Nikolai, who forces her to spend her time doing mathematics and gives her little personal freedom. As he descends into senility, he becomes more and more abusive to her, but she takes refuge in her religion and the "people of God," whom she feeds and communes with. These are wandering Russian mendicants who consciously live a life of poverty. She is a trusting person who does not see the corruption and deceptiveness of people around her. Marya is not beautiful, but she has luminous eyes that reflect the beauty of her soul. She raises Andrei's young son and eventually marries Nikolai and enjoys a happy marriage.