Up until the 15th century Korean was written entirely using chinese characters. Since this required learning several thousand and complicted characters only those with lots of time and money for education werre literate and only a tiny number of aristocrats were able to read and write fluently.

In 1446 the fourth king of Joseon Dynasty, Sejong the Great, published a document called Hunmin Jeong-eum Eonhae the discribed a new alphabet that was specifically designed to be easy to learn.

Hunmin Jeong-eum Eonhae written using
Chinese characters as well as Hangul

Hangul was very successful in spearding literarcy to women and the undereducated but was resisted by some scholars and elited who say it as a threat to their special status and who insisted that Chinese characters were only legitimate writing system. In fact it was so successfuk that it was outlawed by the Tyrant King Yeonsan-gun after commoners made hangul posters mocking him.

After his death Hangul made a comeback,often mixed with some Chinese characters.

Mixture of Chinese characters and Hangul written verticaly

Hangul was also banned once again in Japanese-occupied Korea right before the beginning of World War II in an attempt to make Japanese the official language.

As soon as the war ended Hangul once again