One of Napoleon Bonaparte greatest accomplishments of all time was the great defeat and fall of the Russian Empire to the Grande Armée. He would go on to free the serfs (Often call a key part of his victory), give Finland back to the Kingdom of Sweden, expand the Kingdom of Poland, and create a French-dominated Cossack Hetmanate in the Ukraine.
But what if he lost in Russia and lost big? What if he did not free the serfs? If he was not ready for the Russian winter?