A Weapon of War - The History of Gunpowder in Korea
Korean military forces began to use gunpowder, which they called "fire medicine," from the early 14th century, but could not manufacture it. China, which had invented gunpowder, kept the manufacturing process secret to outsiders. Choi Mu-seon (1325–1395), a military commander and inventor during the last decades of the Goryeo Dynasty, learned the secret of manufacturing potassium nitrate, a critical ingredient in gunpowder, from a Chinese trader. Two other ingredients necessary for making gunpowder, sulphur and wood charcoal, were easily obtainable locally.
Choi perfected Korean gunpowder manufacturing, and also invented guns and other firearms using gunpowder. He inspired the royal government to establish the Office of Firearms (Goryeo), and under his leadership it developed 18 different types of weapons. His motivation in developing gunpowder and firearms was to defeat the Japanese pirates marauding on the shores of the Korean Peninsula. In 1378, Goryeo established a special firearms brigade. Using ships armed with firearms, Choi's special forces won a great victory over Japanese pirates attacking the southwestern shore of the country in 1380.
However, General Yi Seong-gye, who toppled Goryeo and founded the Joseon Dynasty, failed to promote the further development of gunpowder manufacturing. However, his successors revived the military use of gunpowder and firearms. King Sejong used locally manufactured gunpowder and firearms to fight the Jurchens on the northeastern border of the country. By the fifteenth century, the Joseon government drastically reduced the use of gunpowder for fireworks to reserve it for military use.
Potassium nitrate, the most critical ingredient for gunpowder, was manufactured under strict supervision of the government officials, with the sites deep inland to protect secrecy from the Japanese pirates. Korea's gunpowder manufacturing technology improved over time, and in the 17th century, two Korean books on the technology were published.
During the Japanese invasions of 1592-8, gunpowder played an important role in defeating the Japanese. Admiral Yi Sun-sin's famed turtle ships were fitted with canons, which shot cannonballs through the mouths of the turtle-shaped ships for up to a mile to destroy Japanese warships. Japan was far behind Korea in gunpowder and firearms at the time, and therefore the Japanese navy could not withstand the Korean navy with better firearms.
China highly regarded the Korean gunpowder manufacturing and military use of firearms during the Joseon Dynasty, and Japan tried hard to catch up with it throughout that era.
- Choi Mu-seon
- Office of Firearms (Goryeo)
- King Taejo
- King Sejong (Joseon)
- Imjin War
- Yi Sun-sin
- Turtle ships