The army was so huge that it was nearly impossible to keep military formation intact, and the greater part of the army dissolved into straggling, sprawling mobs.
Many of the soldiers pillaged the homes, livestock, and fields of the local peasants.
Nearly 20,000 army horses died from lack of water and fodder on the way to Vilnius.
The homes of the peasants were so filthy that they seemed to be alive with cockroaches.
Napoleon initially had no real reason to invade Russia.
During the Battle of Friedland in June of 1807, Napoleon’s army defeated the Russian army, and on July 7, 1807, France and Alexander I of Russia signed the Treaties of Tilsit, which made the two countries allies (and, among other things, prohibited Russia from doing business with Britain).
It appeared that the skeletons were the remains of soldiers.
A microbe called typhus, spread by a scourge of lice.
The supply columns stayed slightly ahead of the soldiers, so food was readily available, and the soldiers were in good health.
Though military hospitals were established along the route to Poland in Magdeburg, Erfurt, Posen, and Berlin, there was little need for their services.
The typical battlefield diseases of dysentery and other intestinal diseases began to appear, and though new hospitals were set up in Danzig, Königsberg, and Thorn, they were unable to deal with the large numbers of sick soldiers sent back to the rear.
Several days after crossing the Nieman, a number of soldiers began to develop high fevers and a red rash on their bodies.