Gunpowder was the first chemical explosive and propellant. Prior to the invention of gunpowder, many burning devices had been used, including Greek fire. Gunpowder stood alone as an energetic material. The invention of gunpowder is usually attributed to Chinese alchemy, and is popularly listed as one of the "Four Great Inventions" of China. The invention was made perhaps as early as during the Tang Dynasty (9th century), but certainly by the Song Dynasty (11th century). Knowledge of gunpowder spread throughout the Old World as a result of the Mongol conquests of the 13th century. Other inventions in these dynasties would be the magnetic compass, and paper money.
The tang and song dynasties changed the Chinese society because they were well education, they were among the first to actually believe that education came first. They also had their upper class become upper class not because of land ownership, but because of education and scholar officials and civic duties. The gentry became a larger upper class made of scholar officials and their families; they attained their status through education and civil service positions.