By 1808, Alexander I was starting to get upset with his new ally Napoleon, primarily over the "Grand Duchy of Warsaw," a French-controlled Polish state; Alexander had always hoped that Poland would belong to Russia. Napoleon called a meeting of all his puppet monarchs at Erfurt, Saxony, on September 1808. However, this larger meeting was only an excuse for Napoleon to confront Alexander. Napoleon hoped that the arraying of all of Europe's nobility in one place would impress Alexander. It did not.
1809 saw the eruption of an Austrian War of Liberation, which the French quelled quickly however, with the aid of German forces from the Confederation of the Rhine, at the Battle of Wagram. As punishment, Napoleon took some of Austria's territory and added it to the Grand Duchy of Warsaw.
This year also marked Napoleon's 40th birthday (and Josephine's 46th). Suffering from something of a mid-life crisis, the emperor started becoming extremely concerned that he had no heir. Both Napoleon and his wife were no longer really in love with each other, and both had numerous affairs. Since 1807, Napoleon had been seeing Polish Countess Marie Walewska (the affair lasted until his exile in Elba). Although Josephine pointed out that the lack of an heir was probably not her fault (she had already borne two children by her earlier husband), Napoleon divorced her.
Napoleon now began negotiations to find a suitable wife. Napoleon sought a young woman, with many childbearing years still before her, as well as a woman of appropriate noble standing. Czar Alexander rebuffed Napoleon's inquiries about his sister, but Austria, under Metternich, offered the 18-year-old Archduchess Marie Louise, a Hapsburg. Napoleon and Marie Louise married in 1810, and in 1811, she bore him a son, referred to as the "King of Rome." Somewhat ironically, by marrying Marie Louise, from the Hapsburg family, Napoleon now became the nephew by marriage of Louis XVI, the monarch whom the French Revolution executed. The French Revolution had come full circle; the new rule it had instituted was now once again under the control of the same families it overthrew.
By the End of 1811, Napoleon controlled most of Europe. However, the Continental System was failing to severely damage Britain, and anti- Bonapartist nationalist movements were on the rise throughout Europe. However, few had any idea of how to defeat Napoleon's seemingly invincible army and habitually brilliant use of strategy (although his decisions during this time were becoming less decisive and sharp then they had been when he was younger).
With Napoleon now married to a Hapsburg and the Grand Duchy of Warsaw becoming ever larger, Alexander I decided that the French Emperor had become intolerably powerful. On December 31, 1810, Alexander withdrew Russia from the Continental System. Napoleon rapidly moved his Grand Army, consisting of roughly 700,000 men, into Poland to retaliate this breach in loyalty. The stage was set for Napoleon's fateful Russian campaign.