Sejong the Great (May 6, 1397 – May 18, 1450, r. 1418 - 1450) was the fourth king of the Choson Dynasty of Korea. He is best
remembered for creating the native Korean alphabet Hangul, despite strong opposition from the scholars educated in hanja (Chinese
script). Sejong is one of only two Korean rulers posthumously honored with the appellation "the Great," the other being Gwanggaeto
the Great of Goguryeo.
Early life
Sejong was the third son of King Taejong. When he was sixteen, he became Grand Prince Chungnyeong  and married a daughter of
Sim On of Cheongsong , commonly known as Lady Sim  who later was given the title Princess-Consort Soheon.
As a young prince, Sejong excelled in various studies and was favored by King Taejong over his two older brothers.
Sejong's rise to the throne was different from most other kings. The eldest prince, Yangnyung (양녕대군), viewing himself as lacking in
the requisite skills for kingship, believed that Sejong was destined to become king. Together with the second prince Hyoryung, he
believed it was their duty to place Sejong as king. So they acted extremely rudely in the court, and soon were banished from Seoul.
This ploy of the two princes ultimately brought Sejong to the throne. The eldest prince became a wandering traveler and lived in the
mountains. The second son travelled to a Buddhist temple, where he became a monk.
In June 1418, King Taejong abdicated and Sejong was crowned King of Joseon (in August of the same year) and began his rule.
(Taejong helped in military as ex-king for 4 years, and died in 1422)

King Sejong the Great made a great impact on Korean history with his introduction of Hangul, the native phonemic alphabet system for
the Korean language.
Before the creation of Hangul, only members of the highest class were literate. Hanja, the written language of that time, represented
the Korean spoken language by using Chinese characters. One would have to learn the Chinese language in order to read and write
with Hanja. Cumbersome, it disadvantaged the lower classes.
King Sejong presided over the introduction of the 28 letters of the Korean alphabet in order that Koreans from all classes could read
and write. He also attempted to establish a cultural identity of his people because they had their own written language. First published
in 1446, anyone could learn Hangul in a matter of days, and although banned 60 years later it experienced a revival in post-WWII Korea
where it enjoys widespread usage today.

Strengthening of Korean Military
King Sejong was an effective military planner. During his era, he sent an army to destroy the increasing number of Japanese pirates
appearing on Korean shores. Naval engagements quieted much pirate activity, and led to the invasion of the Japanese island of
Tsushima. Korea controlled the island after this and Korean civilians were allowed to live in Tsushima. After King Sejong's rule,
however, Tsushima fell back into Japanese control.
On the northern border, he established four forts and six posts (Hangul :Hanja :to safeguard his people from the hostile Chinese and
Manchurian nomads living in Manchuria. He also created various military regulations to strengthen the safety of his kingdom. King
Sejong supported the advancement of Korean military technology and cannon development increased. Different kinds of mortars and
fire arrows were tested as well using gunpowder.
In 1433, Sejong sent Kim Jong-seo, a prominent general, north to destroy the Manchu. Kim's military campaign captured several
castles, pushed north, and restored Korean territory, roughly the present-day border between North Korea and China.

Sejong overall, supported literature, and encouraged high class officials and scholars to study at the court. King Sejong also oversaw
the creation of Hangul and announced it to the Korean people in the Hunminjeongeum, which was an announcement composed of both
Hangul and Hanja.
Although most of the government officials and the aristocracy opposed the usage of Hangul, lower classes embraced it, became
literate, and were able to communicate among one another easily.
Sejong's personal writings are also highly regarded. He composed the famous Yongbi Eocheon Ga (“Songs of Flying Dragons”, 1445),
Seokbo Sangjeol (“Episodes from the Life of Buddha”, July 1447), Worin Cheon-gang Jigok (“Songs of the Moon Shining on a Thousand
Rivers”, July 1447), and the reference Dongguk Jeong-un (“Dictionary of Proper Sino-Korean Pronunciation”, September 1447).
Sejong established the Hall of Worthies Jiphyeonjeon) in 1420 in the royal palace, Sejong gathered intellectuals from around Korea. The
scholars of the Hall of Worthies documented history, drafted documents and compiled books on various topics. Korea culturally
advanced through King Sejong's encouragement.
Following the principles of Neo-Confucianism, Sejong was also a humanitarian who proclaimed that there must be three trials before a
final judgment is reached, and he prohibited brutality in the punishment of criminals, such as flogging.

Sejong is also credited with technological advances during his reign. During his rule, Jang Yeong-sil (also, Chang Yongsil), who worked
for the Palace Guard, became known as a prominent inventor. Jang was naturally a creative and smart thinker as a young person.
However, Jang was at the bottom of the social class. Sejong noticed Jang's skill and immediately called him to his court in Seoul. Upon
giving Jang a government position and power to invent anything, the officials protested, believing that a low class person could not
rise to power as a noble or a higher class. Sejong instead believed that Jang had the skill and supported his projects.
Jang invented the world's first rain gauge and created some significant water clocks and sundials.
King Sejong wanted to help the farmers so he decided to create the farmer's handbook. The book contained information about the
different farming techniques that he told the scientists to gather in different regions in Korea. Depending on the land of the farmers, he
allowed them to pay more or less taxes. By this action, many farmers had fewer worries about keeping alive. Once the palace had a
surplus of food, King Sejong shared the food with the poor peasants or farmers who needed it.

End of Reign 1450
Sejong died at the age of 53 and was buried at the Yeong Mausoleum  in 1450. His successor was his first son, Munjong.
The street Sejongno and the Sejong Center for the Performing Arts – both located in central Seoul – are named after King Sejong, and
he is depicted on the South Korean 10,000-Won note.

Father: King Taejong
Mother: Queen Wongyeong  
Queen Soheon
King Munjong , 1st Son.
Grand Prince Su-yang, 2nd Son. later King Sejo.
Grand Prince Anpyeong, 3rd Son.
Grand Prince Im-yeong , 4th Son.
Grand Prince Gwangpyeong, 5th son.
Grand Prince Gumseong, 6th son.
Grand Prince Pyeongwon, 7th son.
Grand Prince Youngeung, 8th son.
Princess Jeongso, 1st daughter.
Princess Jeong-eui, 2nd daughter.
Movements - 24

Pattern Meaning
SE-JONG is named after the greatest Korean King, Se-Jong, who
invented the Korean alphabet in 1443, and was also a noted
meteorologist. The diagram represents the king, while the 24
movements refer to the 24 letters of the Korean alphabet.