The Russian Empire penetrated Europe as Europe's age of nationalism began. The retreat of Napoleon Bonaparte after his failed invasion brought Russia into the heart of Europe. and the war began.
Source Citation SNYDER, TIMOTHY. "Nationalism in Tsarist Empire." Encyclopedia of Russian History. Ed. James R. Millar. Vol. 3. New York: Macmillan Reference USA, 2004. 1003-1010. World History in Context. Web. 12 Feb. 2014.