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The Joseon One

Written by Beston Toh, Jiayi Fan, Sindie Gavira

 Statue of King Sejong at Gwanghamun Plaza.  By  Republic of Korea , via  Wikimedia Commons .  CC BY-SA 2.0 .

Statue of King Sejong at Gwanghamun Plaza.

By Republic of Korea, via Wikimedia CommonsCC BY-SA 2.0.

No other king in Korea was as singularly revolutionary as Sejong the Great.

The fourth King of the Joseon Dynasty of Korea (r. 1418–1450 CE) believed it was his duty as King to look after the people. A King that saw no differences between the people of Korea and foreigners of his country, he considered all his subjects as the “People of the Heavens”. Sejong the Great was a man who treated the people of his kingdom as beings of heavenly origin.

The love for his people was only rivalled by his thirst for knowledge. Under the rule of King Sejong, Korea thus embraced her Golden Age with the peak of scientific achievements.

Grounded in Neo-Confucian principles, he encouraged scientific and educational advancements, and ruled his subjects with the principle of benevolence. He is remembered today as the King who liberated the ancient written language from the nobility for the masses, and as the most capable ruler in Korean history with his groundbreaking innovations in science and literature.



For all of King Sejong’s inventions and reforms brought an age of prosperity for Korea, it was only possible due to his deeply-held beliefs in the importance of learning and education. King Sejong recognized the class segregation between his people as a problem, where illiteracy in the lower classes resulted in a widening social gap and a non-collective progress. This prompted him to champion universal literacy. He also held a strong enthusiasm for reading, which is clearly evident especially as he remarked:


No classical or historical works have escaped my attention, and although I am now unable to remember with ease due to my age, I do not stop my reading, because as I read, my thoughts are awakened, and many of these thoughts become deeds in my administration of the State. Seen in this light, reading is indeed a source of great benefit.
(Diamond Sutra Recitation Group, 2007).

In 1420 CE, King Sejong established the Hall of Worthies - the Jiphyeonjeon - consisted of twenty Confucian scholars to act as his advisors, which eventually developed into a royal research institute. The Hall of Worthies conducted various scholarly endeavours, which were then lauded to be the most significant contribution to King Sejong’s reign of the Golden Age. One of the most well-known would be the Hunmin Jeongeum, which served as a document of instruction for the Hangul language (renamed in 1912 CE), the national language of Korea.

The Hunmin Jeongeum (The Proper Sounds for the Instruction of the People), disseminated in 1446 CE, was a 33-page manual distributed to the masses containing the first twenty eight Korean alphabets (more alphabets were added later on). It was one of the greatest milestones in Korean History, as it released the language of the nobility to the masses, and consequently became a universal language for all. The first paragraph of the Hunmin Jeongeum is shown below, where King Sejong said:


The language of our people is different from that of the nation of China and thus cannot be expressed by the written language of Chinese people. Because of this reason, the cries of illiterate peasants are not properly understood by the many in the position of privilege. I feel the plight of the peasants and the difficulties faced by the public servants and am saddened by the situation.


 The first paragraph of the Hunmin Jeongum, written in Classical Chinese.  By  English Wikipedia . Owned by Jeonsongwoo as attributed in  Original Source .  Public Domain .

The first paragraph of the Hunmin Jeongum, written in Classical Chinese.

By English Wikipedia. Owned by Jeonsongwoo as attributed in Original Source. Public Domain.

Initially faced with strong opposition and labelled “barbarian” by his own ministers, it was not until after his death that people began to recognize his ingenuity. With its humble beginnings as a language for informal correspondence, it eventually emerged as the common language uniting all classes. The alphabet was designed from scratch, along with new grammar and syntax rules which bore little similarities to the previously used Classical Chinese script. 

King Sejong also held Confucian beliefs in high esteem and proclaimed his decision to rule with Confucian virtue of benevolence in his inauguration. Believing that his subjects should learn Confucian ethics and morals, he instructed the scholars to gather literary works of Confucian principles on human relationships in both Korean and Chinese history. This led to the development of the Samgang Haengshildo (Conduct of the Three Fundamental Principles in Human Relationships), another significant academic endeavour of the Hall of Worthies. (Diamond Sutra Recitation Group, 2007)



From unravelling the mysteries of herbal medicines, to uncovering the secrets of the cosmos, scientific advancements during the 15th century were unmatched in East Asia during King Sejong’s reign. The Golden Age of Korea was from 1392 to 1592 CE, which began with the ruling of King Taejong. However, it was during the reign of King Sejong that Korea peaked in its scientific achievements.

Korea was the only country in the 15th Century that had the ability to observe meteorological changes through the use of a quantitative measuring device. In pursuit for precise measurements, scientists of King Sejong’s court invented the water gauge, an instrument for precise measurements of rainfall. With that, the government was able to measure and record rainfall across the country by utilizing this highly systematic method for over four hundred years. (Diamond Sutra Recitation Group, 2006).

 A replica of a water clock invented by the royal scholars of King Sejong's rule in Yeouido Park.  By  InSapphoWeTrust  from Los Angeles, California, USA, via  Wikimedia Commons .  CC BY-SA 2.0.

A replica of a water clock invented by the royal scholars of King Sejong's rule in Yeouido Park.

By InSapphoWeTrust from Los Angeles, California, USA, via Wikimedia CommonsCC BY-SA 2.0.

However, the sky was not the limit as science was pushed to the boundaries of space. During his reign, many new astronomical observatories were built. Most notably was the great astronomy observation platform in the Gyeongbokgung Palace. The construction took 7 years to complete, and King Sejong sent mathematicians, astronomers, and technicians to China to study astronomy observational instruments. Through this innovation, astronomers of that period were able to develop an independent calendar. (Diamond Sutra Recitation Group, 2006)

Besides charting out the constellations of the stars, the earth was also mapped out. One of the prominent achievements in geography is the World Map drawn by Joseon geographers in 1402 CE.  The map contained a depiction of Europe, Africa, and the Far East. National measurements were taken to produce a complete map of the country, and it became a map of the highest quality in comparison to others produced during the same period. (Diamond Sutra Recitation Group, 2006)

One of the most important and critical achievements during King Sejong’s reign was in the field of medicine. The Hyangyak Chipsongbang (The Great Collection of Native Korean Prescriptions) boasts a total of 703 Korean native medicine and was completed in 1433 CE. The Hyangyak Chipsongbang was the catalyst that started the independence from Chinese medicine. Another publication, the Uibang Yuch’ui (The Classified Collection of Medicinal Prescriptions), a medical encyclopedia, was also completed in 1445 CE, which contained 153 different Korean and Chinese texts. (Selin & Shapiro, 2003)



It is my hope to gather knowledge of many effective farming techniques and make them known to the farmers of Hamgil and Pyongan. Therefore, inquire among the experienced farmers in Kyongsang Province about their methods of tilling, sowing, weeding, harvesting, and crop rotation, and discover also the nature of soil appropriate for the five main varieties of crop.


King Sejong’s belief in serving his subjects to improve their lives led to many agricultural innovations. In order to improve the lives of the farmers, he commissioned two civil ministers to write the book Nongsa Jikseol (literally translated as Straight Talk On Farming) in 1429 CE. It was the very first farming handbook ever written, and contained various agricultural subjects and techniques for the farmers to elevate farming productivity. As a result of his visionary work, a grain surplus of 5 million bushels of rice was established for the poor farming families. (Diamond Sutra Recitation Group, 2006)

King Sejong also ensured that the farmers did not have to worry about taxes; he allowed them to pay accordingly to the economic climate at the time. During hard times, farmers only needed to focus on working for their families’ survival, and not on how much taxes they needed to pay.

The manifestations of natural disasters were also regarded to be divine reflections of the King’s capabilities. If the people were resentful and thought the King to be incapable, their grievances could reach the skies and bring down natural disasters. Thus when a 7-year drought happened after King Sejong took power in 1418 CE, he ordered food supplies to be distributed to the centre of the capital. When fire wiped out 2170 houses in 1425 CE, he ordered for wells to be dug, fences to be constructed, and roads to be widened; all for fire prevention (Ha & Lee, 2011).

He said:

Rulers should have a mind to care for the people. The fire is a warning for me, exposing my misdeeds in the past and heralding what lies ahead.


Officials under his reign also began to measure the amount of precipitation in order to better manage droughts and floods through the invention of the rain gauge. All these have been highly regarded as one of the earliest and most comprehensive geographical records for the early Joseon dynasty, which aided long-term climate studies.



 King Sejong the Great as depicted on the 10,000 won banknote.  By  The Bank of Korea , via  Wikimedia Commons . 

King Sejong the Great as depicted on the 10,000 won banknote.

By The Bank of Korea, via Wikimedia Commons

King Sejong was a man who had put his faith in his people and in science, who led his people into the peak of Korea’s Golden Age, and one who built the bridge that liberated the common folks’ tongue. His significant literary and scientific innovations solidified the Korean sovereignty, and created an independent Confucian identity from the Chinese dynasty of the time.

King Sejong ultimately raked the soil for the seeds of modern Korea to flourish, and his voice resonates in the people's hearts till this day.

Lauded as King Sejong the Great, he is indeed worthy of the appellation.



Diamond Sutra Recitation Group. (2006). King sejong the great: The everlasting light of korea (1st printing 2006, 2nd printing 2007. ed.). Pohang, Korea: Yong Hwa.

Ha, K., & Lee, Y. (2011). Wells in the historical records of the joseon dynasty, korea. Ground Water, 49(2), 295-299. doi:10.1111/j.1745-6584.2010.00759.x

Hall of Worthies. (n.d.). In Wikipedia. Retrieved 23 Nov 2016.

Hunminjeongeum. (n.d.). In WikipediaRetrieved 23 Nov 2016.

Lee, K. (1997). Korea and East Asia. Westport, Conn.: Praeger. p. 86

Sejong the Great. (n.d.). In Wikipedia. Retrieved 23 Nov 2016.

Selin, H., & Shapiro, H. (2003). Medicine across cultures. history and practice of medicine in non-western cultures. Kluwer Academic Publishers.