《水经注·卷十三》
王莽时称厌狄。建武十九年，世祖把这地方封给代国宰相堪，立为侯国，过去牵招就在这里杀掉韩忠。
应劭曰：当桓都山作城，故曰当城也。又径故代东而西北流注祁夷水。
During the reign of Wang Mang, it was called Yandi. In the nineteenth year of Jianwu, the Emperor Shizu gave this place to the Prime Minister of Dai, Kan, and established it as a vassal state. In the past, Qian Zhao had killed Han Zhong here.