What are some of the most important inventions from the Middle Age?

7. Gunpowder changed the world

Gunpowder is a mixture of saltpeter (potassium nitrate), sulfur, and charcoal. Chinese monks first discovered the mixture in the 9th century CE, possibly while devising medicines. The technology reached the Middle East around the 13th century and was brought to Europe by traders and crusaders soon afterward.

Sir Roger Bacon conducted experiments to find the best ratio of ingredients and is generally credited with arriving at the modern formula and with describing in detail the process for making gunpowder.