History of Yanbian

In the Ming Dynasty, Yanbian was governed by the Jianzhou Guard, and in the late Qing Dynasty the area was divided into the Yanji and Hunchun subprefectures. From 1644 to the 1800s the Manchurian administrators of the Qing state attempted to separate northeast China, politically and ethnographically, into a “Manchuria” to which they could retreat in case an ethnically Han Chinese dynasty regained control over China. However, this effort failed because of the trading and agricultural opportunities available to Han Chinese migrants in the northeast region which made it profitable to evade the rules, as well as later Qing relaxation of the same rules to discourage Russian encroachment.

In the 19th century, Korean immigrants migrated en masse from the Korean peninsula to China. After the foundation of the Republic of China, a second wave arrived. Of the 2 million ethnic Koreans in Manchuria at the time of the communist takeover, 1.2 million remained in the region after the end of World War II. Many participated in the Chinese Civil War, most on the side of the Chinese communists. When the civil war was over, the new Chinese government gave Koreans their own autonomous region in 1952. Yanbian was upgraded to an ethnic autonomous prefecture in 1955.

Korean (Joseon) migration into northeast China began in any significant numbers in the last quarter of the 19th century and was mainly motivated by economic hardship on the Korean side of the border. After the Japanese annexed Korea in 1910, a small but significant number of migrants also came to Manchuria for political reasons.

In 1952, the Korean migrants composed some 60% of the local population, but by 2000 their share had shrunk to 32%. The Chinese authorities subsidize Korean language schools and publications, but also take measures to prevent an emergence of Korean irredentism in the area. From the late 1990s the Koreans voluntarily assimilated into mainstream Chinese culture with increasing speed, often switching to daily use of Chinese and choosing to attend the Chinese language schools.

Source From: https://en.wikipedia.org/wiki/Yanbian_Korean_Autonomous_Prefecture#History