War and Peace is a novel by the Russian author Leo Tolstoy, which is regarded as a central work of world literature and one of Tolstoy's finest literary achievements. War and Peace is perhaps best known as one of the longest novels ever written.

The novel chronicles the history of the French invasion of Russia and the impact of the Napoleonic era on Tsarist society through the stories of five Russian aristocratic families. Portions of an earlier version, titled The Year 1805, were serialized in The Russian Messenger from 1865 to 1867. The novel was first published in its entirety in 1869.