The Song dynasty was founded by Emperor Taizu of Song in 960 in China and continued until 1279 with the last Emperor Zhao Bing. And is historically credited as one of the most brilliant cultural epochs, with unprecedented commercial development, artistic achievements, and most important for this question military technology.
One of the most important features for the success of Song dynasty was the development in weapons technology. The gunpowder was advanced during the Song dynasty, a weapon still unknown in any other part of the world. Early flamethrower, small packages of gunpowder wrapped in paper or bamboo were attached to arrows and ignited with a fuse, explosive, and cannons. All those achievements enabled them to survive despite the military setbacks.
