The introduction of firearms would forever change the face of warfare. It is believed that gunpowder was first developed in the 9th century by Chinese alchemists searching for an elixir of immortality. As early as AD 492, the Chinese noted how saltpeter (one of the primary ingredients for gunpowder) burned with a purple flame. Finding that mixing saltpeter with sulfur and charcoal did not provide immortality, the Chinese instead used gunpowder in fireworks. As the fireworks evolved, the Chinese began using gunpowder in weapons, developing early rockets for use on the battlefield. Muslim traders gained knowledge of gunpowder around 1240-1280, and further developed it for use in cannons. During the Battle of Ain Jalut, the Mamluks used these early cannons against the Mongols. The use of gunpowder and cannons was later adopted by Europeans, who brought these resources to Europe and continued to develop new weapons.
Further innovations in firearm technology eventually led to the development of matchlock guns. The Portuguese continued to refine the matchlock, developing the arquebus in the 15th century. The arquebus was a smoothbore gun and could be fired from the shoulder (like modern day rifles). Although it was considered a low-velocity firearm, the arquebus could penetrate plate armor at short distances, whereas at longer distances the ball fired from the gun usually failed to penetrate steel armor. The guns accompanied Portuguese traders, and were introduced to Japan in 1543.
The Japanese were impressed with the firearm, and began developing their own version in large numbers. The arquebus eventually became one of the most important weapons in Japan. Tactics were further revolutionized during the Battle of Nagashino, when Oda Nobunaga assigned his arquebusier’s with three guns, and split the tasks with loaders who would reload the weapons after being fired. When the Japanese invaded Korea in 1592, Japanese units were divided up among spearman, archers, and arquebusiers. During the Edo Period, firearms were eventually phased out of service, used mainly for hunting and target practice. When the US Naval fleet led by Cdr. Matthew Perry arrived in 1854, Japan once again renewed their efforts for modernization, and firearms became a staple weapon in the Japanese military.