After the defeat of the Qin soldiers and the battle, they realized that it was not feasible to cross han wei and attack Zhao geographically. Therefore, it is necessary to have a long flat highland. As can be seen in the figure, the Shangdang controls the four of the taihang eight: Xuan Guanxing, Taihang, Baixing, and Fukou. Connecting Hadong with Hanoi, Xuanguan was a shortcut from guanzhong to present-day Hebei. Tai Hung, Bai Xi and Xuan Guan, like Xuan Guan, are not only the partial gates of the ancient Hanoi region, but also the passage of Hanoi into the Shang Dang. Fukou was the most important, not only in connection with the party and Handan, but also in control of the main communication route between the Zhao capital Handan and the former capital Jinyang. It can be seen from this that the gains and losses of the Shangdang are directly related to the survival of the Zhao state.
Qin Shi Huang was able to successfully destroy Zhao because he controlled the Shangdang Heights. First, the main force of the Zhao state was used to contain the main force, and then two armies went eastward: one from Jinyang to the south of Xiajing, and the other from Xuanguan to the north to attack Handan. Looking at the picture, we can see that even if Li Mu was not killed by the traitors, he could not change the outcome of the eventual collapse of the Zhao Kingdom.
In 268 BC, the Qin army took the Wei state of Huaiyi through Xuanguan. Huaiyi is located at the throat of the Danshui River into the Yellow River, and controlling Huaiyi can block the waterway channels connecting the Shangdang area to the outside world. In 264 BC, Bai Qi attacked nine cities in Korea and completely controlled Hedong, which became the rear of the Qin state for the Battle of Changping. In 263 BC, Bai Qi again left Hanoi through Xuan Guanxing. In 262 BC, Bai Qi attacked the Wild King. Then, Bai Qi controlled Tai Xingxing again. As a result, the Shangdang region of South Korea became an enclave. In view of the condescending geographical situation of Shangdang Heights against Handan, Zhao Guohukou accepted Feng Ting's offer of land, and the Battle of Changping finally broke out.
After Lian Po was ordered, he immediately led his army through Fukou to Changping, and then turned along the Taoqing River into the Xiaodongcang River into the Huishi (present-day Gaoping). Soon, Lianpo laid out three defensive lines according to the situation of the mountains and rivers: the Defense Line of the Hundred Mile Stone Great Wall, the Defense Line of the Danhe River, and the Defense Line of the Empty Cangling Ridge.
The picture shows the three lines of defense built by Lianpo.
When Lian Po was deploying to the party, Wang Gong, the left governor of the Qin state, had already led his troops from Xianyang. They took the Weishui River into the Yellow River and traced it up to the mouth of the Fenhe River, and then entered the Fenhe River to reach Xintian. This section of the waterway is mostly, combined with the Situation of Qin Jin and Qin Wei fighting for Hexi and Hedong for hundreds of years, the Qin Army is very familiar with the hydrological situation of this section of the waterway. In addition, it was far more convenient to transport grain by water than by land (cf. the Battle of Panzhou in 647 BC).
After Wang Gong arrived in Xintian along the Fen River, he immediately followed the Xun River and its tributaries up to HuangFu, the dangerous Wuling Pass. Wuling Pass is more than 1400 meters above sea level, which is the commanding height of this area, and the Qin army can climb on it and look east and west to make enemy observations. After walking down Wuling Pass, the Qin army turned into the Meihe River Valley to reach Mayi, a beach with abundant water and grass, and then the Qin army quickly turned into the Qinshui River to reach Duanshiyi.
When the Qin army arrived at Duanshiyi with anger, it immediately launched a continuous attack on the Lianpo Empty Cangling Defense Line. Qin rebuked the soldiers and beheaded Zhao Pei. In June, he dedicated himself to the Zhao Army and took the second lieutenant. In July, the Zhao army built a wall and defended it. Qin attacked his base again, took the second lieutenant, defeated his position, and captured the western fortress wall. In the end, the Zhao army abandoned the empty Cangling Ridge and retreated to the east bank of Danshui. If from the perspective of defense, Danshui is more suitable than Empty Cangling, at least it is not attacked by the Qin army at patio pass.
Lianpo relied on the Danshui, which was wide and deep in the valley, and made every effort to strengthen the defensive line. At the same time, the commanding heights of Daliang Mountain and Hanwang Mountain can overlook the Dan river valley for tens of miles, and the enemy and us are moving, and almost all of them are controlled by Lianpo. Since then, "Lian Po has been waiting for Qin, Qin has challenged, and Zhao Bing has not come out." The Qin army, which was strong and eager to fight, was helpless and could never cross the Dan River, and the war fell into a stalemate. Thus, the military struggle gave way to political mediation. However, King Xiaocheng of Zhao, who had just reigned for three years, was obviously not a rival to King Zhaoxiang of Qin, who had enjoyed the kingdom for 46 years. Soon, the State of Zhao was caught up in the divisive plan of the State of Qin. Lian Po was replaced by the young and vigorous Zhao Kuo, and the Qin general Bai Qi also quietly came to the front line.
Shi Zai Zhao Kuo first "learned to be easy to restrain and easy to place military officials", and then won bai qi's plan to lure the enemy to go deeper. The Zhao army attacked the Qin wall for a long time and continued to add soldiers and horses. At this time, a Qin army traced the water of the Qin River to the rear of the Baili Stone; a Qin army broke through the Zhao Army's Danhe defense line along the Xiaodongcang River, and then the main force of the Qin army was quickly filled, completely isolating the main force of the Zhao army from the heavy troops. In this way, the main force of the Zhao army was surrounded by the main force of the Qin army and the odd troops in the triangle of more than fifty kilometers in the area of The Yanshi-Changpingguan-Guguan-Huishi, and the heavy troops of the Zhao army were surrounded by the Qin army in the Daliangshan area. The main force of the Zhao army has more food and less food, and the heavy troops have less food and more food, and the two sides cannot communicate with each other.
And so on, this has never been a precedent in the art of war. In fact, the key to Baiqi's success is to take advantage of the geographical characteristics of the Changping area, which seems to be open in the river valley and has very few actual exports. In order to prevent the possible reinforcements from tearing open the Baili Stone Defense Line, Prince Zhaoxiang of Qin went to Hanoi and urgently requisitioned men over the age of 15 to Changping in exchange for the Qin hukou. Zhao Jun was in a desperate situation. After 46 days, Zhao Kuo divided the main force into four teams, organized a series of surprise attacks, and finally he personally went into battle, led the elite troops to force a breakthrough, and was immediately shot by the Qin army. The main general was killed in battle, and the Zhao army surrendered, and the Qin state also lost more than half of its strength through this battle.