During his reign the power of the Buddhist heirarchy was reduced and a system for recording the Korean language phonetically was introduced.
Editors. "Korean cultural efflorescence under the reign of Sejong". The Literary Encyclopedia. First published 01 March 2010; last revised 30 November -1.
[http://www.litencyc.com/php/stopics.php?rec=true&UID=9643, accessed 25 April 2015.]