- 1794: Used for reconnaissance and battlefield surveillance during the French Revolutionary Wars
- 19th Century: Used during the Franco-Prussian War and the American Civil War
- 20th Century: Used during WWI, WWII, the Vietnam War, and several other conflicts.
- Present Day: Still being used by military forces around the world for surveillance and reconnaissance.
How:
- Reconnaissance and Aerial Photography: Hot air balloons provided a vantage point high above the battlefield without being detected.
- Command and control: Used for observing battlefields and sending messages back to headquarters.
- Psychological warfare and intimidation: The sight of a hot air balloon descending on an enemy position could scare them into surrendering.