On what date did XXX end?
Battle of Eylau
The Battle of Eylau or Battle of Preussisch-Eylau, 7 and 8 February 1807, was a bloody and inconclusive battle between Napoléon's Grande Armée and a Russian Empire army under Levin August, Count von Bennigsen near the town of Preußisch Eylau in East Prussia.
8 February 1807