Xuan-de: Year 3, Month 5, Day 4
16 Jun 1428
The Yan-jing Police Office was established under the Che-li/Jing-an Pacification Superintendency in Yun-nan, was established. At this time, the pacification superintendent advised that the territory under his jurisdiction was frequently being attacked and occupied by troops who had deserted, civilian fugitives or yi persons from beyond the borders. Thus, the people were not at peace in their occupations. He requested that the Yan-jing Police Office be established and that the interpreter Wang Jing be appointed as police officer. Both requests were approved.
Zhong-yang Yan-jiu yuan Ming Shi-lu, volume 18, page 1045