明前期,瓦剌活跃在蒙古高原历史舞台上。也先时,其势力所及,西起中亚,东接朝鲜,北连西伯利亚南端,南临明边,致使“漠北东西万里,无敢与之抗者”。①同时也先还挥戈南下,直指明朝京师,在“土木之役”中,以两万轻骑大败号称五十万的明军,俘获英 Early Ming, Wala active in the historical stage of the Mongolian plateau. Also first and foremost, its power comes from Central Asia in the west, North Korea in the east, Siberian southern end in the north and Mingbian in the south, resulting in “Mobei miles and miles, no dare to resist.” ① At the same time, they also started to go southward and directed the Ming Dynasty capitalists. In the battle of civil engineering, they were defeated by 20000 Qingliang troops who claimed to be 500,000.