War of the Third Coalition 18051805 to 1806
French Empire and Satellites
The War of the Third Coalition was a European conflict spanning the years 1803 to 1806. During the war, France and its client states under Napoleon I, defeated an alliance, the Third Coalition, made up of the Holy Roman Empire, Russia, Britain and others. Great Britain had already been at war with France following the resumption of hostilities resulting from the breakdown of the Peace of Amiens and remained the only country still at war with France after the Treaty of Pressburg. From 1803–05, Britain stood under constant threat of a French invasion. The Royal Navy, however, secured mastery of the seas and decisively destroyed a Franco-Spanish fleet at the Battle of Trafalgar in October 1805.