The Zhao State established Handan as its capital, also the present city Handan of Hebei Province. Zhao neighbored the Wei State on the west, the Yellow River and Zhanghe River on the south, the Qi State on the east separated by the Qinghe River, and the Yan State on the north separated by the Yi'shui River. It also bordered minority nationalities of Hun, Loufan and Linhu on the northwest.
Because troopers of the minorities harassed Zhao frequently, threatening the safety of Zhao so as to have affected its living, Zhao's courageous and insightful King Zhaoyong, also King Zhao Wulin, in the year 366 B.C. led his army personally, and finished the state of Zhongshan. He soon vanquished another two enemies of Hulin and Loufan and forced them to the far north.
By 302 B.C., Zhao's territory had expanded to incorporate the present Tuoketuo and Wulateqianqi of Inner Mongolia, and the Great Bend area of the Yellow River, where immigrants afterward developed the agriculture.
To consolidate its north-border defense, Zhao began building a wall on its north in 300 B.C. The wall started from a point northeast to present Wei County of Hebei Province, ran west and passed through the north of Shanxi, turned off to the northwest and entered Inner Mongolia, hiked along the range of the Yinshan Mountains and went down to the west along the southern foot till present Langshan County of Inner Mongolia.
To defend against the Wei State, Zhao built another wall on the south. As wars between the two states mainly took place on the banks of the Zhangshui River, Zhao extended the north embankment of the River and constructed it into a wall. It is recorded in Shi Ji that "King Zhao Wuling called in State Secretary Louhuan and consulted, 'the previous King saw wars and turns of the sates and thought the best way to resist attacks from the Zhangshui and Fushui Rivers was to develop our south border area. That's why he afterward built a wall along this boundary.'" The "previous King" in the quotation was King Zhao Wuling's father Suhou. Also recorded in Shi Ji is that "Suhou began to build the wall in his 17th year of reign. " So we can infer that this wall was built within Suhou's ruling time. The site of the wall is near now Lizhang and Cixian County of Heibei Province, where the two rivers are still flowing.
Besides the two walls above, Zhao constructed another wall, which started from the point south to present Daixian County of Shanxi, ran southwest to Shanxi, headed on along the north feet of Hengshan and Luya Mountains till meeting the first branch of the Yellow River. This wall was probably the earliest wall Zhao built on its north.
