Michel Ney, 1st Prince de la Moskowa, 1st Duke of Elchingen was a French military commander and Marshal of the Empire who fought in the French Revolutionary Wars and the Napoleonic Wars.

The Battle of Eylau, or Battle of Preussisch-Eylau, was a bloody and strategically inconclusive battle on 7 and 8 February 1807 between Napoleon's Grande Armée and the Imperial Russian Army under the command of Levin August von Bennigsen near the town of Preussisch Eylau in East Prussia. Late in the battle, the Russians received timely reinforcements from a Prussian division of von L'Estocq. After 1945, the town was renamed Bagrationovsk as part of Kaliningrad Oblast, Russia. The engagement was fought during the War of the Fourth Coalition, part of the Napoleonic Wars.