- 09-January-1799 : British Prime Minister William Pitt the Younger introduces an income tax of two shillings to the pound to raise funds for Great Britain's war effort in the Napoleonic Wars.
- 17-October-1805 : Napoleonic Wars Battle of Ulm: Austrian General Mack von Leiberich is forced to surrender his entire army to Napoleon after being surrounded.
- 07-November-1805 : Napoleonic Wars Battle of Trafalgar: British naval fleet led by Admiral Horatio Nelson defeats a combined French and Spanish fleet off the coast of Spain; however, Admiral Nelson is fatally shot.
<!<!<!IMAGEIMAGEIMAGE> The Lewis and Clark Expedition arrives at the Pacific Ocean.
- 11-November-1805 : Napoleonic Wars Battle of Durenstein: 8,000 French troops attempt to slow the retreat of a vastly superior Russian and Austrian force.
- 16-November-1805 : Napoleonic Wars Battle of Schongrabern: Russian forces under Pyotr Bagration delay the pursuit by French troops under Murat.
- 02-December-1805 : Napoleonic Wars Battle of Austerlitz: French troops under Napoleon decisively defeat a joint RussoRussoAustrian force.
- 23-January-1806 : Grenville succeeds William Pitt the Younger as wartime Prime Minister of the United Kingdom, upon Pitt's death this day amidst worsening health caused by the stresses of the Napoleonic Wars
- 07-September-1812 : Napoleonic Wars Battle of Borodino: The bloodiest battle of the Napoleonic wars ends in a draw.
- 24-October-1812 : Napoleonic Wars Battle of Maloyaroslavets: An inconclusive encounter between the French vanguard and a Russian force leads Napoleon to decide to retreat along the same line as his advance, with disastrous results.
- 07-November-1812 : Napoleonic Wars Battle of Vyazma: Napoleon's retreating army is defeated.