- Oct 7 Carbon paper patented in London by inventor Ralph Wedgwood
- Oct 8 British forces lay siege to French port of Boulogne using Congreve rockets, invented by Sir William Congreve
- Oct 9 Prussia declares war on France
- Oct 14 Battle of Auerstadt-French beat Prussians
- Oct 17 Former leader of the Haitian Revolution, Emperor Jacques I of Haiti was assassinated after an oppressive rule.
- Oct 27 The French Army enters in Berlin