On 2 December 1805, one year and one day after his coronation as emperor, Napoleon I began the battle against the rulers of Austria and Russia. This battle was a prime example of conception, methodical preparation and masterful execution and emphasised Napoleon's tactical genius. It was studied for years at war schools throughout Europe. Albert Ponod, using Napoleon's diary and the archives of the generals who commanded the units of the Grande Armée, allows us to follow the preparations, the correction of mistakes by the Emperor himself and the hour-by-hour progress of the operations. A work that makes the reader a privileged spectator of the great battle of Austerlitz.