The reasons for the Battle of Weinan

The reasons for the Battle of Weinan

Both the Battle of Chibi and the attack on the south failed, so Cao Cao set his sights on the remote areas of Guanzhong. Cao Cao lost on the southern front, so he decided to expand to Liangzhou. Affected by the news, Ma Chao, Han Sui and others raised troops to resist, and fought with Cao Jun in Tongguan and Weinan in Guanzhong. In the end, Cao Cao used tricks to win and suppress Guanzhong.

The Battle of Weinan was a battle in which Prime Minister Cao Cao defeated the Guanzhong coalition forces such as Ma Chao and Han Sui in the 16th year of Jian'an (211). In the Battle of Weinan, Cao Cao claimed to be a successful example of flexible use of troops in which "the changes in the troops are not the same", which attracted much attention at the time and later generations.

In the 18th year of Jian'an (213), when Cao Cao was promoted to the Duke of Wei, Emperor Xian of the Han Dynasty praised Cao Cao for his achievements in the Weinan War in the edict: "Ma Chao and Cheng Yi worked together to help the evil, and the coast was occupied. He and Tong pursued what they wanted, and sacrificed their lives in Weinan, offering thousands of traps, and then settled the border and pacified the Rong and Di. This is also the merit of the emperor."

Pre-war Situation

At the end of the 13th year of Jian'an (208), Cao Cao suffered the biggest defeat in his life in the Battle of Chibi, with more than half of the casualties. In the fourteenth year of Jian'an (209), Jiangling, an important southern town, was lost, which dealt a huge blow to Cao Cao's plan to advance southward. In March of the 14th year of Jian'an (209 years), Cao Cao stationed in Qiao County to build light warships and train naval forces, preparing to continue his march to the south.

In July, Cao's army arrived at Hefei from the Tuoshui and Huai Rivers. However, considering the hard work of the soldiers and the prevalence of epidemics due to successive years of campaigning, they did not continue to advance southward, and returned in December. The area around Qiao County. In the fifteenth year of Jian'an (AD 210), Cao Jun basically rested and reorganized. The difficulty of advancing southward lay ahead, so Cao chose the Guanzhong, Liangzhou and Bashu regions in the west as his next marching target.

The troops guarding Guanzhong are actually a coalition composed of ten large and small warlords. Han Sui and Ma Chao were the core of this alliance, but they did not have a strict reporting relationship. Usually, they are scattered in their own territories. When situations of interest arise, they will gather together to fight against the enemy together.

At that time, the Guanzhong Group was nominally subordinate to Cao Cao. In the sixth year of Jian'an (201), when Cao Cao and Yuan Shang were fighting fiercely in Hebei, the Guanzhong Group also helped Cao Cao's Sili Colonel Zhong Yao defeat Gao Gan and Nan Shanyu's regiment. The powerful Guanzhong Group is a huge threat to Cao Cao's march to the southwest. Cao Cao would never dare to let a powerful and unstable military group exist in Guanzhong behind him when his army penetrates deep into the dangerous areas of Hanzhong and Bashu.

Military Planning

Guanzhong has always been a land of four fortresses: the steep Qinling Mountains to the south, the protection of Tongguan and the Yellow River natural barrier to the east, and the Longshan and Liupan Mountains to the west. There are high mountains, and to the north are Ziwu Ridge and Huanglong Mountain on the Northern Shaanxi Plateau. Cao Cao mainly used three routes to attack Guanzhong:

1. North Road: leave Hedong and cross the Yellow River from Pubanjin to the west.

2. Middle Road: along the main road, enter through Tongguan.

3. South Road: Go south to Wancheng first, then take a detour through Wuguan and Lantian. Since the Qin Empire unified China based on Guanzhong, Emperor Gaozu of the Western Han Dynasty also relied on Guanzhong's geographical advantages to unify the country.

Since ancient times, there has been a saying of "One Hundred and Two Qin Passes". Due to the dangerous terrain in Guanzhong, 20,000 soldiers can resist the attack of a million troops. Especially when attacking Guanzhong from the Central Plains area to the east, it is basically an unfavorable situation for attacking from the top, especially through Tongguan. Therefore, if Cao Cao wants to defeat the Mahan Group, which occupies a dangerous location in Guanzhong and has strong military strength and combat power, he must outwit them.