Russia, 1805. Napoleon Bonaparte's French army has invaded Austria, drawing Russia into the war against him. Everyone in aristocratic Russian society is rattled - except hot-headed Pierre Bezukhov, who admires the French emperor's politics. Pierre is an outcast in society, and the illegitimate son of one of Russia's wealthiest men. But now his father is close to death and his scheming relatives are vying for the old man's fortune - though they expect Pierre to be left with nothing.
Pierre's dearest friend Prince Andrei Bolkonsky is excited for war with Napoleon. For him it offers a chance to find purpose in life by fighting on the front line. Unhappily married to a beautiful socialite, Lise, he plans to leave her behind at his fierce father's remote country estate and seek military glory for himself. The army under Andrei's wise mentor General Kutuzov expects a swift victory. But when the French unexpectedly prove their military might, Andrei is thrust into a dangerous battle.
Pierre's other great friend is Natasha Rostova - a beautiful, lively young woman growing up fast and desperate to experience more of the world. When she sees love blossom between her brother Nikolai and his childhood sweetheart Sonya, she is inspired for the first time with romantic thoughts of her own. As the men ride off to war, Natasha and Sonya are left behind to wait and wonder if they will ever return.
Andrei and Nikolai have managed to survive their first run in with the French, but a new and more terrible battle is just around the corner. Pierre finds it hard to settle into married life with Helene. Natasha and Sonya are excited to hear news from the front line.
After Pierre takes part in a duel, his life goes in a surprising new direction. Natasha and Sonya receive a couple of unexpected proposals. Nikolai makes a mistake with disastrous consequences for his family.
Natasha agrees to a long engagement, but finds it hard to deal with Andrei's absence after temptation crosses her path. Countess Rostova and Anna Mikhailovna both attempt to steer their sons towards the young heiresses, although they both have plans of their own.
Napoleon invades Russia and preparations are underway for another huge battle with him. The French army marches east and Marya is scared to find out that her family is in danger and her father is refusing to listen to reason.
The French army makes its way into Moscow and chaos descends on the city. The Rostovs have no choice but to flee and Natasha is stunned by an unexpected fellow traveller whilst Sonya is asked to make a massive sacrifice for her family.