《后汉书·列传·南蛮西南夷列传》
哀牢位于西南，距洛阳有七千里，显宗在那裹设立哀牢、博南两个县，将益州郡西部都尉所管辖的六个县划出来，合为永昌郡。
西南去洛阳七千里，显宗以其地置哀牢、博南二县，割益州郡西部都尉所领六县，合为永昌郡。
Ailao is located in the southwest, 7,000 miles from Luoyang. Xianzong set up two counties, Ailao and Bonan, and combined the six counties under the jurisdiction of the western governor of Yizhou to form the Yongchang county.