May 15, 1397 CE
Birth of Yi Do (future King Sejong)
Yi Do (later King Sejong) is born to King Taejong and Queen Wongyeong in Hanyang (Seoul). He would become the fourth king of Joseon. #history #Korea
Chronological Storyline (23 Milestones)
Sep 10, 1418 CE
Ascension to the Throne
Sejong ascends the throne after his father Taejong abdicates. His reign begins a period of peace and prosperity. #history #Korea
1420 CE
Establishment of the Hall of Worthies (Jiphyeonjeon)
Sejong creates the Hall of Worthies (Jiphyeonjeon), a royal research institute of Confucian scholars. This body plays a key role in developing Hangul and other scholarly works. #history #education
By 문화재청, KOGL Type 1, https://commons.wikimedia.org/w/index.php?curid=107937744
1429 CE
Publication of Nongsa Jikseol (Guide to Proper Farming)
An agricultural treatise compiled under Sejong's direction, detailing farming techniques to improve crop yields and alleviate famine. #agriculture #science
By 정초(鄭招), 변효문(卞孝文) - http://www.emuseum.go.kr/detail?cateClass=&cateListFlag=&keyword=%EB%86%8D%EC%82%AC%EC%A7%81%EC%84%A4+&pageNum=7&rows=9&reltRows=10&sort=&highQualityYn=&isImgExistOp=&mckoglsvOp=&isIntrstMuseumOp=&filedOp=&detailFlag=&dq=&ps01Lv1=&ps01Lv2=&ps01Lv3=&mcSeqNo=&author=&ps06Lv1=&ps06Lv2=&ps08Lv1=&ps08Lv2=&ps09Lv1=&ps09Lv2=&ps09Lv3=&ps09Lv4=&gl05Lv1=&gl05Lv2=&ps12Lv1=&ps15Lv1=&culturalHerNo=&publicType=&detailedDes=&thema=&storySeq=&categoryLv=&categoryCode=&mobileFacetIng=&location=&facet1Lv1=&facet1Lv2=&facet2Lv1=&facet3Lv1=&facet3Lv2=&facet4Lv1=&facet4Lv2=&facet5Lv1=&facet5Lv2=&facet5Lv3=&facet5Lv4=&facet6Lv1=&facet6Lv2=&facet7Lv1Selected=&facet7Lv1=&facet8Lv1=&gl27Lv1=&gl27Lv2=&gl27Lv3=&gl27Lv4=&gl28Lv1=&gl28Lv2=&gl28Lv3=&gl29Lv1=&gl30Lv1=&mcgpyear1=&mcgpyear2=&mcginves=&mcgchalj=&mcgchams=&facetGL27Lv1=&facetGL27Lv2=&facetGL27Lv3=&facetGL27Lv4=&facetGL28Lv1=&facetGL28Lv2=&facetGL29Lv1=&facetGL30Lv1=&mcgwonpn=&keywordHistory=%EB%86%8D%EC%82%AC%EC%A7%81%EC%84%A4+&showSearchOption=&intrstMuseumCode=&returnUrl=%2FheaderSearch&selectMakerGroup=0&radioSearchCheck=unifiedSearch&headerPs01Lv1=&headerPs01Lv2=&headerPs01Lv3=, Public domain, https://commons.wikimedia.org/w/index.php?curid=172431707
1432 CE
Development of the Celestial Globe (Honcheonui)
The royal astronomer Jang Yeong-sil builds a celestial globe (honcheonui) to track stars and planets, advancing Joseon astronomy. #science #astronomy
1433 CE
Completion of the Compilation of Medical Texts
Sejong sponsors the compilation of Hyangyak Jipseongbang, a comprehensive Korean medical encyclopedia, integrating Chinese and native remedies. #medicine #science
Jul 1, 1434 CE
Completion of the Water Clock (Jagyongru)
Jang Yeong-sil completes a self-striking water clock (jagyongru) for the royal palace, an advanced timekeeping device with automated bell and drum. #science #invention
1435 CE
Invention of the Rain Gauge (Cheugugi)
Sejong orders the creation of standardized rain gauges (cheugugi) to measure precipitation for agricultural planning. This is one of the first such devices in the world. #science #invention
By Steve46814 - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=32668697
1437 CE
Invention of the Sundial (Angbuilgu)
A bowl-shaped sundial (angbuilgu) is invented to show time accurately, used widely across Joseon. #science #invention
1438 CE
Northern Campaign: Establishment of Four Forts and Six Posts
Sejong launches a military campaign against Jurchen tribes, establishing four forts and six posts to secure the northern border. #military #history
1441 CE
Improvement of Movable Metal Type Printing
Sejong commissions the development of improved movable metal type (Gapinja) to print scholarly works, enhancing literacy. #technology #printing
Dec 20, 1443 CE
Creation of Hangul (Hunminjeongeum)
Sejong and the Hall of Worthies create the Korean alphabet Hunminjeongeum (Hangul), designed to be easy to learn and represent Korean sounds accurately. #language #invention
By Sejong the Great of Joseon - http://www.cha.go.kr/korea/heritage/search/Culresult_Db_View.jsp?VdkVgwKey=11,00700000,11, Public domain, https://commons.wikimedia.org/w/index.php?curid=4927531
Sep 20, 1446 CE
Official Promulgation of Hunminjeongeum
Sejong officially announces the new alphabet in the document 'Hunminjeongeum' (The Correct Sounds for the Instruction of the People), detailing its principles and usage. #language #history
1447 CE
Publication of Yongbieocheonga (Songs of Dragons Flying to Heaven)
The first literary work written in Hangul, an epic poem celebrating the founding of Joseon. It demonstrates the alphabet's expressiveness. #literature #language
By Nuyos at English Wikipedia - Transferred from en.wikipedia to Commons., Public domain, https://commons.wikimedia.org/w/index.php?curid=51892809
1449 CE
Compilation of Seokbo Sangjeol (Life of Buddha)
Sejong oversees the compilation of Seokbo Sangjeol, a biography of Buddha written in Hangul, promoting Buddhist texts in the new script. #religion #language
May 18, 1450 CE
Death of King Sejong
King Sejong dies at age 52 after a reign of 32 years. He is buried in Yeongneung tomb. His legacy includes Hangul, scientific advancements, and cultural flourishing. #history #Korea
1451 CE
Publication of Sejong Sillok (Annals of King Sejong)
The official historical records of Sejong's reign, the Sejong Sillok, are compiled posthumously, providing detailed accounts of his achievements. #history #historiography
1454 CE
Compilation of Dongguk Tonggam (Comprehensive Mirror of the East)
Sejong had initiated a history of Korea; the Dongguk Tonggam is later completed under his successor, covering Korean history from ancient times. #history #historiography
By 三猎 - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=54605367
1461 CE
Publication of Gyeongguk Daejeon (National Code)
A comprehensive legal code is completed, building upon Sejong's legal reforms, laying the foundation for Joseon governance. #law #history
By 猫猫的日记本 - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=53314698
1485 CE
Expansion of Hangul Usage in Official Documents
Hangul becomes more widely used in government documents and vernacular literature, though classical Chinese remains the elite script. #language #history
By metalslick - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=63996191
1493 CE
Publication of Sejong's Medical Texts: Dongui Bogam Precursors
Medical compilations from Sejong's reign influence the later Dongui Bogam (1613), a classic of Korean medicine. #medicine #history
By en:Heo Jun - http://100.nate.com/dicsearch/pimage.html?i=222742003&en=&pg=search&v=44, Public domain, https://commons.wikimedia.org/w/index.php?curid=7430010
1500 CE
Construction of Jagyongru Replica
A replica of the water clock is built, preserving Sejong's technological legacy. #science #history
1543 CE
Influence of Sejong's Agricultural Reforms on Later Policies
Sejong's agricultural manuals continue to guide farming practices, contributing to food security. #agriculture #history