Jeongjo’s Jangyongyeong Guard
Jeongjo created the Jangyongyeong royal guard with an inner garrison in the capital and an outer one at Hwaseong in Suwon; through the chogye munsin system he retrained young officials.

Kim Deuksin & al. 김득신 · Public domain · Source
After founding the Gyujanggak (1776), Jeongjo had promising officials under thirty-seven retrained there (chogye munsin, 1781). The Jangyongwi guard of 1785 became the Jangyongyeong in 1793, a royal army to counter the other garrisons controlled by the factions.
Jeongjo appointed Park Je-ga, Yu Deuk-gong and Yi Deok-mu, sons of concubines, as Gyujanggak editors, and had magistrates run the village codes themselves to curb the local gentry. He issued the Daejeon tongpyeon code (1785), freed trade by the 1791 reform, and built Hwaseong. The guard was disbanded in 1802 after his death.
