User:Hawkeye7/War/Selected anniversaries/September 3
- 36 BC - In the battle of Naulochus, Marcus Vipsanius Agrippa, admiral of Octavian, defeats Sextus Pompeius, son of Pompey, thus ending Pompeian resistance to the Second Triumvirate.
- 1260 - The Mamluks defeat the Mongols at the Battle of Ain Jalut in Palestine, marking their first decisive defeat and the point of maximum expansion of the Mongol Empire.
- 1650 - Third English Civil War: Battle of Dunbar (1650).
- 1651 - Third English Civil War: Battle of Worcester - Charles II of England is defeated in the last main battle of the war.
- 1783 - American Revolutionary War: The war ends with the signing of the Treaty of Paris by the United States and the Kingdom of Great Britain.
- 1939 - World War II: France, the United Kingdom, New Zealand, and Australia declare war on Germany.
- 1943 - World War II: Mainland Italy is invaded by Allied forces for the first time in the war.