The First Empire was at its height during the Jena-Auerstadt campaign of 1806. The campaign was a classic of Napoleonic tactics, as Marshal Davout held one German army at bay while Napoleon concentrated his forces to defeat the main one.
This excellent book combines an informative narrative with paintings oft he battles and a superb collection of images of uniforms and equipment from the period - all in color.
By the same author and available from Casemate
Borodino-The Moskova: The Battle for the Redoubts
Wagram: At the Heyday of the Empire