《明史·志·卷六十六》
洪武三年，升杭州、江西、燕山、青州四卫成为都卫，又设置河南、西安、太原、武昌四个都卫。
洪武三年，升杭州、江西、燕山、青州四卫为都卫，复置河南、西安、太原、武昌四都卫。
In the third year of Hongwu, the four guards in Hangzhou, Jiangxi, Yanshan and Qingzhou were promoted to metropolitan guards, and four further metropolitan guards were established in Henan, Xi'an, Taiyuan and Wuchang.