Yong-le: Year 6, Month 3, Day 13
9 Apr 1408
Imperial orders were sent to the Xin-cheng Marquis Zhang Fu, regional commander of Jiao-zhi. The orders read: "The Jiao-zhi Provincial Administration Commission has memorialized that the three areas of Po-lei, Qiu-wen and Ai-liu are narrow passes into Jiao-zhi and are affected by miasmic vapours. The official troops find it difficult to dwell in these places. It has proposed raising native forces and establishing guards in nearby Si Subprefecture, Tai-ping Prefecture and Tian Subprefecture. Then, like in the systems in force at Tong Pass in Shaan-xi and Qu-tang in Si-chuan, the military forces will be subordinate to Guang-xi, while the people will be subordinate to Jiao-zhi. This proposal has been approved for your convenience."
Zhong-yang Yan-jiu yuan Ming Shi-lu, volume 11, page 1046