A map of Western Russia at the time of Napoleon's invasion in 1812. The map shows the borders of Russia, Prussia, and the Duchy of Warsaw at the time, the city of Kovno where Napoleon crossed the River Niemen on June 24, 1812, the crossing site at Grodno, and the cities of Vilna, Smolensk, Borodino, Moscow (entered on September 14, 1812), the retreat route to Malo-Yaroslavetz, Viazma, Krasnoi, and the crossing of the River Berezina (November).