1397 – 1450
King Sejong was the fourth king of the newly established Choson Kingdom. Albeit he was the third born son of King Taejong and Queen Min, he was able to ascend to the throne after both his elder brothers were disqualified from the throne. His eldest brother Prince Yang-nyeong had lost his title due to his rude and aberrant behavior in court; whereas his second eldest brother Prince Hyoryeong became a Buddhist monk, thus removing himself from succession. In 1418, King Sejong ascended to throne after his father abdicates the throne in favor of him.
King Sejong was a revolutionary king of his time. From day one in his inauguration speech, King Sejong made it a point to let his people know that he will govern them with genuine benevolence. This ideal of thinking was a result of King Sejong’s studies in Mencius’s Neo-Confucian teachings that emphasized benevolence, societal improvement, and the pursuit of knowledge. With his Confusian policies, he brought about many legal amendments.
In terms of military developments, King Sejong was advised by his father for the first four years of his reign. After learning the ropes from the former king, Sejong was able to introduce many improvements to his military, both technologically and tactically. He encouraged the development of innovative weapons, as well as employed the use of gunpowder in advanced weaponry. Cannons, mortars, and fire arrows are some examples of the type of weaponry that was greatly enhanced with the support of King Sejong.
In just one year after ascending throne, King Sejong was able to capture Tsushima Island – an island off south eastern coast of Korea – in his Gihae Eastern Expedition. The island was occupied by Japanese pirates who raided trading ships; stealing trade goods and kidnapping shipmates. King Sejong’s military troops captured the island by defeating the pirates and rescuing the kidnapped victims.
Despite his achievements in science, literature, and politics, King Sejong’s greatest achievement by far was the invention of the Korean alphabet, known as Hangul. Prior to the creation of hangul, Korean was only a dialect and had no written language. The kingdom’s officials and aristocrats had adopted the Chinese writing system, in which only elitists were able to read. In order to increase public literacy, Sejong and his advisers devised a simple alphabetic system that would represent the Korean language. This system was meant to be easily learned by all people within a matter of days. The different combinations of the 14 consonants and 10 vowels are able to generate the entire Korean language. Hangul was officially announced in 1446 and became widespread throughout Korea. It is used to this day as the official writing system for both Korean nations. Hangul is deemed scientifically as one of the most logical writing systems on Earth, due to its simplicity and straight-forwardness.
King Sejong not only encouraged technological development in the military, but also technological advances in literature and science. It was with his support that moveable metal type for printing and mulberry-fiber paper was improved. Rain gauges, celestial globes, musical instruments, sundials, water clocks, and star maps are examples of the many other scientific devices that King Sejong sponsored. He also established a food bank to store grain surplus in preparation of times of famine for poor farming families. He was truly one of the greatest kings in Korean history.