The history of writing in the Korean peninsula begins with the Chinese characters arriving in Korea together with Buddhism during the Proto-Three Kingdoms era from BC 57 to AD 660. It was adapted for Korean and became known as Hanja, and remained as the main script for writing Korean through over a millennium alongside various phonetic scripts that were later invented such as Idu and Gugyeol. Mainly privileged elites were educated to read and write in Hanja, In the interest of decreasing illiteracy, King Sejong the Great developed an alphabetic writing system in the 15th Century. This is known today as Hangul. The King felt that writing Hanja was difficult to learn, so the illiterateracy was increasing. Hangul was originally designed to replace Hanja entirely.
Unfortunately, the system was denounced by the Korean aristocrats in Conservative Party due to its simplicity. It used to be called "Morning letter" meaning that it can be learnt within one morning. The Korean nobles were against the use of Hangul. However, it quickly spread nationwide, and accordingly increased the level of literacy in Korea. It played vital role in reducing the knowledge gaps in between the aristocrats and the peasants. Despite that the Hangul was widely used by all Korean classes, the official documents were still written in Hanja during the Choseon era due to the insistence of a conservative aristocratic class.
Today, Hangul is largely used in everyday life in Korea and officially recognised as Korean Characters. Hangul is used by the Korean people in both North Korea and South Korea and by Koreans throughout the world. Korean is the fourth most popular foreign language in China, following English, Japanese, and Russian.