长城词典·土木堡之变明英宗正统十四年（1449年），英宗朱祁镇亲自率领的明军在土木堡（今河北怀来县西）被瓦剌军打败，英宗被俘，史称土木堡之变也称土木之变。土木堡之变后，明朝掀起了大规模修筑长城的高潮。 明宪宗成化三年时（1467年），对东起山海关西至雁门关一段长城进行了全面修筑，将山海关、喜峰口、古北口、居庸关、倒马关等连接了起来。明武宗正德年间，修筑宣府镇及大同镇所管辖的长城一千余里。明穆宗隆庆年间，戚继光主持重修蓟镇、昌镇及部分真保镇长城，修筑敌台1007座。至此，明朝的北部边防得以强固。 Great Wall dictionary·Battle of Tumu BuIn 1449，emperor Yingzong led his Ming troops to fight against Mongolian tribe Waci in Tumu Bu （Huailai county，Hebei Province）. Emperor Yingzong was captured by the Mongolian troop. This campaign is thus called Battle of Tumu Bu in history. After this defeat，the Ming Dynasty began to construct the Great Wall on a large scale. In 1467，emperor Xianzong reconstructed the Wall from Shanhai Pass （in the east） to Yanmen Pass （in the west），linking Shanhai Guan，Xifeng Kou，Gubei Kou，Juyong Guan and Daoma Guan altogether. Later Qi Jiguang began the repair work on the segment of Jizhen and Changzhen. Meanwhile，he also directed the construction of 1007 watchtowers along the wall. At his time，the northern defense system of the Ming Dynasty was strengthened.
