Origin of Hangul
Ledyard holds that the Koreans adopted five core consonant letters from ’Phags-pa, namely ㄱ "g" , ㄷ "d" , ㅂ "b" , ㅈ "j" , and ㄹ "l" . These were the consonants basic to Chinese phonology, rather than the graphically simplest letters (ㄱ "g" , ㄴ "n" , ㅁ "m" , and ㅅ "s" ) taken as the starting point by the "Haerye." A sixth letter, the null initial ㅇ, was invented by Sejong. The rest of the consonants were developed through featural derivation from these six, essentially as described in the "Haerye"; a resemblance to speech organs was an additional motivating factor in selecting the shapes of both the basic letters and their derivatives.
Sejong Science High School
In November 3, 2005, the project about establishing new science high school in Seoul was approved by Ministry of Education and Science Technology. The name of the school, Sejong Science High School, is named after Sejong the Great, the king who created the Korean alphabet; Hangul. In March 24, 2009, the school officially signed in the friendship exchange with DDG-991 Aegis Combat System, generally called "Sejong the Great Combat System".