Starting in 1792, Europe endured almost permanent warfare, as Revolutionary France, with its changing lines of attack, faced off against the other major powers, the monarchies of Great Britain, Austria, Prussia, and Russia. In peace agreements of 1795 and 1797, France expanded its territory to the Rhine. Under the supreme command of the Corsican Napoleon Bonaparte, further military successes followed in Italy. Austria lost its Dutch possessions (Belgium), as well as Milan. The first affiliated republics under French control emerged in Upper Italy. Beginning in 1799, Napoleon successfully led four additional coalition wars (1799–1802, 1805, 1806/07, and 1809) which further contributed to the territorial reorganization of Central Europe.
In Germany, the Principal Decree of the Imperial Deputation [Reichsdeputationshauptschluß] of 1803 eliminated almost all secular territories as well as most free cities. Baden, Württemberg, Bavaria, and Prussia profited from the division of the territories in particular. Bavaria and Württemberg were elevated to kingdoms in 1805, and in the summer of 1806 their leaders openly violated imperial law by uniting with other, elevated southern and western German sovereigns in the Confederation of the Rhine [Rheinbund]. The Confederation of the Rhine was obliged to provide military support to Napoleon. After the states of the Confederation of the Rhine formally seceded, the Holy Roman Empire of the German Nation ended on August 6, 1806. Its last ruler, Franz II, had already held the parallel title Emperor of Austria since 1804.
In the following years, additional states joined the Confederation of the Rhine, including the higher-ranking Kingdom of Saxony, the Kingdom of Westphalia (newly created after the grave Prussian defeat in 1806 and governed by Jérôme, a brother of Napoleon), and the Grand Duchy of Berg, which was in the hands of Joachim Murat, one of Napoleon’s brother-in-laws. Apart from all its territories west of the river Elbe, Prussia also lost several large territories in the east. They were formed into the new Grand Duchy of Warsaw and governed by Saxony in a personal union. The new kingdom of Holland was governed by Ludwig, another one of Napoleon’s brothers, beginning in 1806. Napoleon, who had elevated himself to Emperor of France in 1804, also bore the title King of Italy starting in 1805. After the Austrian defeat and the Peace of Schönbrunn of 1809, Austria had to cede territories to Bavaria (Salzburg, North Tyrol), Italy (South Tyrol), France (Illyrian Provinces), Warsaw (West Galicia), and Russia.
Thus, by 1812, the territorial and political might of the two major powers, Prussia and Austria, had been severely diminished. Prussia had sunk to the status of a French vassal. The strengthened or newly created middle-sized states in the Confederation of the Rhine, as well as the new states in Italy and eastern Europe (all of which were under Napoleon’s control) were intended to form an effective counterbalance to Austria. Domestically, French influence spurred the abolition of the outdated feudal system and brought about important political and judicial reforms. After the Battle of the Nations at Leipzig and the collapse of the Napoleonic regime in October 1813, the Confederation of the Rhine dissolved.