Around 1248, the English monk Roger Bacon recorded the formula for gunpowder in his manuscript De secretis operibus artis et naturae. About the same time, Albertus Magnus recorded a formula for gunpowder in his De mirabilius mundi ignium, and Berthold Schwartz experimented with gunpowder in Germany. As these men ushered in the Age of Gunpowder, little did they suspect the major changes gunpowder would create in the social order, political systems, military tactics, architecture, science and industry.
By 1326, cannons were illustrated in Walter de Milimete's manuscript De officiis regum, dedicated to Edward III's accession to the English throne. Edward III later became well known for his use of the cannon in battle.
On August 26, 1346, the English and French armies met in battle at Crecy in northern France. Led by King Philip of Valois, the French army numbered over 40,000 men, while the English army led by Edward III consisted of fewer than 20,000 men. While the two armies seemed badly mismatched, Edward III introduced two new weapons to the battlefield for the first time: the longbow and the cannon.
There were 11,000 longbowmen and two cannons in the English army. The longbowmen practically annihilated the French knights, while it was recorded that the cannon caused the Italian mercenary crossbowmen in service to the French "much discomfort." This is the first documented use of firearms in land warfare.