War of the Third Coalition: Austrian General Mack surrenders his army to Napoleon at the Battle of Ulm.

The Battle of Ulm on 16–20 October 1805 was a series of skirmishes, at the end of the Ulm campaign, which allowed Napoleon I to trap an entire Austrian army under the command of Karl Freiherr Mack von Leiberich with minimal losses and to force its surrender near Ulm in the Electorate of Bavaria.