alternatehistory.com

After the defeat of Austria at Wagram, the Austrian empire was stripped of its access to the ocean and Italian territories plus Austrian Carniola to France, Bohemia to Westphalia, Salzburg and Tyrol to Bavaria, Galicia to Warsaw and Tarnopol to Russia. Hungary was also threatened with separation. As a result, the Russian Empire began to see Napoleonic France as a threat, compounded by the growth of Poland under the Duchy of Warsaw. For Britain, the only success was the capture of French and Spanish colonies in the Caribbean, Latin America and the Indian Ocean over the 1808-1811 timeframe.
On 24 June 1812, the French Grand Army invaded Russia from the Niemen, having caught the Russians preparing for an offensive into Poland. Despite the willingness of the Russian 1st Army to retreat, it was encircled and destroyed on 5 July, with an order to retreat into Russia proper being stopped by orders from Tsar Alexander I to Barclay De Tolly telling him to defend Lithuania at all costs. On 17 September 1812, the 1st Russian Army remnants, plus conscripts and the Russian 2nd Army fought ferociously at Borodino in a desperate attempt to stop the French advance, but was encircled and forced to surrender. With it came the fall of Moscow in 10 days intact. A final offensive in the winter of 1812 inflicted heavy casualties on the Russian Army's last conscripts despite the French Grand Army suffering 150,000 casualties from the Russian offensive and counterattack. This would lead to the Treaty of Novgorod being signed on 30 April 1813, the Russian Army being out of reserves to carry on the fight as the Grand Army entered Novgorod.