War and Peace, Book III, by Leo Tolstoy (Reader - Beware of Spoilers)

So, as you probably guessed that Andrew and Natasha's wedlock does not happen. Natasha is able to nurse the wounded Andrew on a journey out of Moscow and he forgives her for her escapade with Anatole Kaguine but dies in her arms, of course. Peter Bezukov goes through a period of depression, at one time consumed by a plan to personally shoot Napoleon, but rediscovers his good nature while surviving as a prisoner of the French on their retreat from Moscow.
Kutuzov, the old Marshall, after Borodino, manages to avoid another battlefield confrontation with the French as he believes that the invading army will waste itself without the need for another battle. The Tsar too is urged to depend on smaller skirmishes to finally remove the invaders. Nicolas leaves his regiment on the death of his father in order to restore order to the family's affairs by developing his lands in a profitable way with Maria and her fortune beside him.
Peter marries Natasha and scenes of domestic family life return to the story. The final section of the book, the Epilogue, sees Tolstoy put forward his view that individuals cannot manage chaotic events which change history (change established cultural patterns?). Such events are the product of numerous forces at work in people's lives.

War and Peace, Book l by Leo Tolstoy (reader - beware of spoilers)

In the opening scenes, set first in St Petersburg, the fashionable capital with its elaborate manners, and then in Moscow, a more provincial city, we meet members of five families. Incident involving members of these families occurs throughout the trilogy. Andrew Bolkonsky, handsome and dashingly eager for glory; Nicolas Rostov, immature, a delight to his sister and parents, Peter Besukov, clumsy, intellectual, and rudderless with a huge fortune in prospect, are three of this number.
The first two are soon soldiers in the huge parade of the armies before the Emperors of Russia and her ally Austria. Rostov is entranced by the sight of the Tsar and feels that he could die for him. Bolkonsky, too, dreams of battlefield distinction. After the French victory, Napoleon's party on the battlefield come across the body of a young officer apparently struck down at the moment of grasping the colours of a French regiment. They find that the man is not dead although severely wounded. During the battle Rostov had been sent by General Bagration as a messenger with the hopeless task of finding Marshall Kutuzov for orders but he does come across plenty of battle detail for Tolstoy to describe. In St Petersburg after the Russian defeat, Bagration is nevertheless praised by the chattering classes for conserving the lives of his men.

Bolkonsky is feared dead by his father and sister but his young pregnant wife, the 'little princess'. has not entirely given up hope. His sister Maria, highly devout can accept disaster as God's will. The day of Bolkonsky´s momentous return to his family having been left for dead on the battlefield (he was the wounded Russian officer found by Napoleon) becomes also a day of family tragedy.

After his battle experiences, Prince Andrew Bolkonsky is content to settle on the family estate and remain out of society. The young ladies of the families we met in St Petersburg and Moscow come to the fore