Why did Ma Chao arise and attack Tongguan?

Ma Chao attacked Tongguan because Cao Cao tried to attack the land through the territory of Liangzhou warlords such as Ma Chao, not because Cao Cao killed people. In March of the 16th year of Jian 'an (2 1 1), Cao Cao sent Zhong You and Xia to the east of the river, trying to attack Zhang Lu in Hanzhong through the turf of Liangzhou warlords such as Ma Chao. Kansai warlords headed by Ma Chao and Han Sui all suspected that Cao Cao would attack and annex Liangzhou.

Ma Chao thought this was Cao Cao's false plan to destroy the enemy, so he joined forces with ten Guanzhong generals, including Zhang Heng, Liang Xing, Yang Qiu, Hedong candidates Yin Cheng, Li Kan, Ma Wan and Cheng Yi, to raise 100,000 troops against Cao Cao. Ma Chao tried to win over Liu's influence, but was rejected. Ma Chao led the troops to break through and took refuge in Cao Cao.

In order to win over Han Sui, Ma Chao even said to Han Sui, "Now, Ma Chao has abandoned his father and regarded General Han as his father. General Han should also abandon his son and take Ma Chao as his son. " Yan Hang advised Han Sui not to unite with Ma Chao. Han Sui said to Yan Xing: "Now, all the generals happen to coincide, and it seems that one day."

So the Guanzhong Coalition forces elected Han Sui as the commander in chief, then moved eastward, arrived in Huayin, assembled in Weihe River and Tongguan, and built a camp. Tens of thousands of families in Guanzhong fled to Hanzhong to escape the war. History is called "Han Sui-Ma Chao Rebellion".

The result of Tongguan campaign

In this battle, Cao Cao defeated several legions in Guanzhong that held the emperor to make the princes, so that they could not resist together and their strength was greatly weakened. Later, Cao Cao accepted it further, and sent Xia to guard Chang 'an and pacify Han Sui with Zhang He.

Although Ma Chao kept massing his troops, they were all suppressed by Xia, and finally he could only escape to Zhang Lu and Hanzhong. In May of the 17th year of Jian 'an (2 12), Cao Cao killed Ma Teng, an official in Beijing.

Refer to the above? Baidu Encyclopedia-Ma Chao

Refer to the above? Baidu encyclopedia-battle of Weinan