French troops stop an allied invasion of France at the Battle of Valmy.

The Battle of Valmy, also known as the Cannonade of Valmy, was the first major victory by the army of France during the Revolutionary Wars that followed the French Revolution. The battle took place on 20 September 1792 as Prussian troops commanded by the Duke of Brunswick attempted to march on Paris. Generals François Kellermann and Charles Dumouriez stopped the advance near the northern village of Valmy in Champagne-Ardenne.

September 20 is the 263rd day of the year in the Gregorian calendar; 102 days remain until the end of the year.