An elaboration on the origins of Black Powder.

The discovery of black powder is not well-documented in history, and there are several theories about its origins. One theory is that it was first invented by Chinese alchemists in the 9th century, while they were searching for an elixir of immortality. They stumbled upon a mixture of potassium nitrate, charcoal, and sulfur, which when ignited, produced a large flame and a lot of smoke. They began to use this mixture in fireworks and other pyrotechnic displays.
Another theory is that black powder was first used by the Arabs in the 12th century. They were using a similar mixture, made of saltpeter, charcoal, and sulfur, for medicinal and alchemical purposes.
It is certain that the Chinese were the first to use black powder for military purposes. They employed it in rockets and flamethrowers during battles, and by the 12th century, they had developed a crude form of gunpowder, which they used in the form of incendiary bombs.
Black powder was brought to Europe in the late 13th century and it was quickly adopted for use in firearms and cannons. It remained the primary propellant for firearms for several centuries, until it was replaced by smokeless powder in the late 19th century.