Sejong the Great
Before the creation of Hangul, people in Korea (known as Joseon at the time) primarily wrote using Classical Chinese alongside phonetic writing systems based on Chinese script that predated Hangul by hundreds of years, including idu, hyangchal, gugyeol, and gakpil. However, due to the fundamental differences between the Korean and Chinese languages, and the large number of characters that needed to be learned, there was much difficulty in learning how to write using Chinese characters for the lower classes, who often lacked the privilege of education. To assuage this problem, King Sejong created the unique alphabet known as Hangul to promote literacy among the common people. His intention was to establish a cultural identity for Korea through its unique script.
Hangul
The Korean alphabet was designed so that people with little education could learn to read and write. A popular saying about the alphabet is, "A wise man can acquaint himself with them before the morning is over; even a stupid man can learn them in the space of ten days."
The project was completed in late December 1443 or January 1444, and described in 1446 in a document titled "Hunminjeong'eum" ("The Proper Sounds for the Education of the People"), after which the alphabet itself was originally named. The publication date of the "Hunminjeongeum", October 9, became Hangul Day in South Korea. Its North Korean equivalent, Chosŏn'gŭl Day, is on January 15.