Eighteen-year-old German stonemason Jakob Walter served in the Grand Army of Napoleon between 1806 and 1813. His diary intimately records his trials: the long, grueling marches in Prussia and Poland, the disastrous Russian campaign, and the demoralizing defeat in a war few supported or understood. It is at once a compelling chronicle of a young soldier's loss of innocence and an eloquent and moving portrait of the profound effects of all wars on the men who fight them.

Also included are letters home from the Russian front, previously unpublished in English, as well as period engravings and...