Why was invading Russia a bad idea? (Napoleon Bonaparte)

fter taking power in 1799, French leader Napoleon Bonaparte won a string of military victories that gave him control over most of Europe. He annexed present-day Belgium and Holland, along with large chunks of present-day Italy, Croatia and Germany, and he set up dependencies in Switzerland, Poland and various German states. Spain was largely under his hegemony despite continuing guerilla warfare there, and Austria, Prussia and Russia had been browbeaten into becoming allies. Only Great Britain remained completely outside of his grasp.