War of the Third Coalition: Ulm Campaign, Austerlitz and the Peace of Pressburg

Background. The War of the Third Coalition began in 1805 as Britain, Austria, and Russia allied against France. Napoleon, having camped at Boulogne for an invasion of Britain, redirected his forces to the Rhine in August 1805 to confront Austrian and Russian threats. The Grande Armée marched out from Boulogne in late July 1805, and the Austrians invaded Bavaria on 8 September 1805 with an army of about 72,000 under Karl Mack von Leiberich.

Ulm Campaign. The Ulm Campaign involved a large wheeling maneuver by the Grande Armée from late August to mid-October 1805. This maneuver captured an entire Austrian army under Karl Mack von Leiberich. Key engagements included the Battle of Elchingen, where Marshal Ney routed an Austrian corps, and the subsequent surrender of Mack's army near Ulm in the Electorate of Bavaria.

Danube Delaying Actions. Following the Ulm campaign, French forces advanced toward Vienna. Marshals Murat and Lannes captured a bridge over the Danube at Vienna by falsely claiming an armistice. Subsequent engagements at Dürnstein and Schöngrabern involved French troops attempting to slow the retreat of Russian and Austrian forces, setting the stage for the decisive battle at Austerlitz.

Austerlitz and Peace. The decisive engagement of the war occurred at Austerlitz on 2 December 1805, where Napoleon defeated a combined Austro-Russian force. This victory led to the signing of the Peace of Pressburg on 26 December 1805 in Bratislava. The treaty forced Austria to leave the coalition and cease hostilities against France, reinforcing earlier treaties.