In the "Three Kingdoms Zhishu Shu Book Wei Yan Biography", it is recorded that such a passage is recorded, "Yan every time he is revealed, he wants to invite tens of thousands of soldiers, and he will meet with Liang at Tongguan, such as the story of Han Xin, and the bright system is not allowed." Yan every time he said that the light was timid, and he hated himself to be inexhaustible."
Later, the historian Pei Songzhi, who annotated the Romance of the Three Kingdoms, made a detailed quotation below this material:
"Wei Liuyue: Xiahou Shu was the general of Anxi, the town of Chang'an, Liang Yu Nan Zheng and Qunxia planned, Yan Yue: ''Hearing Xiahou Shu is few, the master and son-in-law are also cowardly and unscrupulous. This holiday, yan jing soldiers 5,000, 5,000 negative grain, straight out of the praise, along the Qin Mountains to the east, when the meridian and north, but ten days can reach Chang'an. When the whims are prolonged, they will flee by boat. In Chang'an, there are only Yushi, Jingzhao Taishou, Hengmen Pavilion and The Valley of scattered people. It is still twenty days before the East meets, and the Gong from the Valley of The Slope will be enough to reach. In this way, it can be determined in one fell swoop to the west of Xianyang. Liang thought that this was in danger, it was better to be safe from the Tan Dao, you can take the Long Right flat, and the ten must be conquered without worry, so there is no need to delay. ”
To the effect that Zhuge Liang, who had already arrived in the capital of Hanzhong, Nanzheng, summoned the Generals of the Shu Army to discuss the Northern Expedition, and Wei Yan asked Zhuge Liang to send tens of thousands of troops along the Meridian Valley to attack Chang'an. He believed that the lord who guarded Chang'an was cowardly and unscrupulous, and when he heard that the Shu army had fallen from the sky, he would flee east to Luoyang by boat along the Weishui River. At that time, the main force led by Zhuge Liang left the Xie Valley in the north. Then, the Shu army could take Guanzhong lightly without a fight. When Zhuge Liang heard this, he thought that this plan was too risky, and it was better to occupy long right first, and then condescend to take guanzhong safely, so he abandoned this plan.
The above is all the historical records about the famous "Meridian Valley Conspiracy". So, is Wei Yan's Meridian Valley Plot feasible? In this regard, we can refer to the route direction of the Zixia Noon Road in the late Eastern Han Dynasty.
Meridian Road during the Southern and Northern Dynasties of the Qin and Han Dynasties
The earliest record of the Meridian Road is found in the Book of Han compiled by Bangu in the Eastern Han Dynasty, when the ruler Wang Mang, in order to publicize that his daughter who had been made empress had "Descendants Rui", built a large number of civil engineering to open the Meridian Road from Chang'an to Hanzhong. In fact, the opening and use of the Meridian Road can be traced back to the late Qin and early Han dynasties. The "Ode to the Stone Gate" preserved today clearly engraves a sentence, "Gao Zu was ordained to flourish in Hanzhong, and the Tao was scattered from the meridian to Qin." At that time, the Meridian Road was from Ducheng Village in the southern suburbs of present-day Xi'an City to the Meridian Valley Mouth near the meridian town of Chang'an County, tracing up the valley to the watershed land beam of the meridian valley and the east tributary of Fengyu, and crossing the liang along the fengshui tributary to the south near Yuziping to Shiyangguan. From Shiyangguan to the south, cross the main ridge of the Qinling Mountains to the Xunhe River Valley, a tributary of the Han River, pass through Jiangkou Town, Shaping Street, and Yueheping to the Yuehe River, and then cross the Yuehe River in the south and go up the bamboo ditch, and enter another tributary of the Han River. Follow the south of the Chi River, the business plate, rouge dam, new mine, iron furnace town into Shiquan County, through Wutong Temple, Shifo Temple, Chopsticks Shop and other places to Chihe Town; from Chihe Town to the northwest over Maling Pass, around the north side of the Han River Jiuli Thirteen Bay, through Shi MoPu, Yao Bay to Shiquan County; from Shiquan County to the northwest, through Guyan to Raofeng Street, fold west to Raofengling to Xixiang County Meridian Town, cross the Meridian River into Yang County, northwest around the Han River Golden Fjord Dawan Qu, through Jinshui Town, Youshui Town, Longting and other places into the Han River Plain, across Yang County, Chenggu County Dahanzhong.
The northern section of Shu Province
It is estimated that the overall length of the Meridian Road is more than 1,000 miles, second only to the Old Road but surpassing the Luo Road, the Chu Chuan Road and the Lianyun Trail. Unlike the above roads, the meridian path can follow a short river valley, but the mountain valley road is 880 miles long, comparing the number of watersheds that pedestrians need to read far more than the other lines. What is even more distressing is that there are few residents along this road, and there is only one Anyang City in the middle from Chang'an to Han. Later, an Ankang County was established during the Western Jin Dynasty, and a Shiquan County was established during the Tang Dynasty. Therefore, from the perspective of material supply and security guarantees in terms of marching, Wei Yan's Meridian Valley plot did have great loopholes. In fact, the march was not the most important part of Wei Yan's strategy, and the surprise was Wei Yan's killing move. Judging from the establishment of Hanzhong County at that time, Wei Yan's plot would not go well.
Hanzhong Commandery and shuwei dividing line during the Eastern Han Dynasty
The Book of Later Han records that Hanzhong County was set up by Qin Shi and had a total of nine cities, namely Nanzheng, Chenggu, Xicheng, Baozhong, Qiuyang, Anyang, Xi, Shangyong, and Fangling. The Chronicle of the Three Kingdoms records that after Cao Cao defeated Zhang Lu and annexed Hanzhong in 215, he immediately "divided Anyang and Xicheng into Xicheng Commanderies in Hanzhong and placed Taishou; Fenxi and Shangyong were Shangyong Counties", which was the later Eastern Three Counties. Later, Liu Bei beheaded Xiahou Yuan at the Battle of Dingjun Mountain, and took Xicheng, Shangyong, and Fangling into his pocket. Unfortunately, after Guan Yu defeated Maicheng, the Eastern Three Counties were again offered to Cao Wei by Meng Da. Soon, Meng Da wanted to aid Zhuge Liang's Northern Expedition, and the Cao Wei general Sima Yi rushed to attack and behead him. From then on, Shu Han completely lost control of the Eastern Three Counties, and the city of Anyang (Shiquan), which Qin placed during the Qin Dynasty, also became the forefront of Cao Wei's opposition to Shu Han. It can be seen from this that the marching route planned by Wei Yan was basically under the supervision of Cao Wei, and it was difficult to play an unexpected surprise attack, which was also the root cause of why Zhuge Liang did not use Wei Yan's strategy.
More than 1400 years later, a rebel leader named Gao Yingxiang returned to Guanzhong again with 50,000 tired soldiers through the meridian valley of Hanzhong, but was ambushed by Sun Chuanting, the governor of Shaanxi. Historical records record that Sun Chuanting effortlessly captured the hungry and tired Gao Yingxiang himself, his subordinates Huang Long, the general manager Liu Zhe and other leaders. Perhaps, this is another proof of Wei Yan's Meridian Valley plot.