Chinese Taoist alchemists were the major force behind the early invention of gunpowder. Emperor Wu Di (156-87 BCE) of the Han dynasty financed research done by the alchemists on the secrets of eternal life. The alchemists experimented with the sulfur and saltpeter heating the substances in order to transform them. The alchemist Wei Boyang wrote the Book of the Kinship of the Three detailing the experiments made by the alchemists.
During the 8th century Tang dynasty, sulfur and saltpeter were first combined with charcoal to create an explosive called huoyao or gunpowder. A substance that did not encourage eternal life, however, gunpowder was used to treat skin diseases and as a fumigant to kill insects before its advantage as a weapon was made clear.
The Chinese began experimenting with the gunpowder-filled tubes. At some point, they attached bamboo tubes to arrows and launched them with bows. Soon they discovered that these gunpowder tubes could launch themselves just by the power produced from the escaping gas. The true rocket was born.