Although Cao Cao was a sinister and cunning man, he cherished talents, which made many military generals during the Three Kingdoms period willing to defect to Cao Cao and follow Cao Cao. For example, Zhu Ling, who was a subordinate of Yuan Shao. Later, Yuan Shao sent him to lead three battalions of soldiers and horses to help Cao Cao conquer Tao Qian. After arriving at Cao Cao's account, Zhu Ling found that Cao Cao was fair, capable, and a rare ming lord, so he decided to follow Cao Cao and not go back to Yuan Shao. Because of this, Cao Cao gathered a large number of military generals.
Cao Cao's famous generals included Zhang Liao, Zhang Guo, Xu Huang, Dianwei, and others, and Xun Yu, Guo Jia, Xun You, Jia Xu, Cheng Yu, and others, but in Cao Cao's life, he also missed many military generals, such as Cao Cao, who was particularly fond of Guan Yu, and always wanted to recruit him to his command. Guan Yu was loyal and righteous, and even though he briefly submitted to Cao Cao, he was treated favorably by Cao Cao, and when he learned that Liu Bei was still alive, he insisted on leaving Cao Ying and going to Liu Bei. In addition to Guan Yu, Cao Cao also missed these 4 top advisers.
1. Chen Gong
Chen Gong was a native of Dongwuyang (東武阳, in present-day Xinxian County, Shandong). In the third year of Chuping, after Liu Dai of Yanzhou was killed by the Yellow Turban Army of Qingzhou, Chen Gong won the support of Bao Xin, the chancellor of Jibei, and made Cao Cao the assassin of Yanzhou. Ping Bai could get a piece of land for no reason, which made Cao Cao very grateful to Chen Gong and regarded it as a confidant. Later, Cao Cao killed Bian Rang and other famous soldiers, and Chen Gong felt that Cao Cao was cruel and began to turn against him.
When Cao Cao led an army to attack Tao Qian, Chen Gong persuaded Chen To stay too protective of Zhang Miao, Zhang Chao, Zhang Chao, and Xu Feng, who was engaged in zhonglang, to betray Cao Cao, and they welcomed Lü Bu into Yanzhou. With the help of Chen Gong, most of Yanzhou fell into Lü Bu's hands, but Xun Yu, Cheng Yu, and Xiahou Huan defended Juancheng, Fancheng, and Dong'a Counties for Cao Cao, and eventually helped Cao Cao defeat Lü Bu and retake Yanzhou.
After being defeated by Cao Cao, Chen Gong followed Lü Bu to defect to Liu Bei. Liu Bei did not like Lü Bu, but in order to strengthen his own strength against Cao, he still took Lü Bu into custody and stationed Lü Bu in Xia Pi. Soon after, Lü Bu took advantage of Liu Bei's outings to attack Yuan Shu and captured his Xuzhou.
After obtaining Xuzhou, Cao Cao soon led an army to attack Lü Bu. Lü Bu's strength was inferior to Cao Cao's, and he did not take Chen Gong's advice, resulting in the city of Xia Pi being flooded by Cao's army, and they became turtles in an urn, and both he and Chen Gong were captured by Cao Cao. Cao Cao wanted to persuade Chen Gong to surrender to his command again, but Chen Gong was unwilling to assist him, and Cao Cao was forced to kill Chen Gong, which also caused Cao Cao to miss Chen Gong again, a top strategist.
Second, Xu You
Cao Cao, Xu You, and Yuan Shao were all young friends. After Dong Zhuo rebelled, Cao Cao and Yuan Shao joined forces to attack Dong Zhuo, but his young friend Xu You did not come to Cao Cao, but defected to Yuan Shao's command, assisting Yuan Shao in his struggle for the world. After Dong Zhuo was killed, Cao Cao and Yuan Shao became the two most powerful princes at that time, and if they wanted to take the world, they had to defeat each other.
In the fifth year of Jian'an, Cao Cao and Yuan Shao launched a decisive battle at Guandu. At that time, Yuan Shao's strength was stronger than Cao Cao's, and Cao Cao almost poured out of the nest in order to defeat Yuan Shao, which led to the emptiness of his rear. Xu You suggested that Yuan Shao send a cavalry to attack Xuchang. After the fire in Cao Cao's rear, there will definitely be great confusion in the army. At this time, Yuan Shao took the opportunity to attack and was able to defeat Cao Cao in one fell swoop, but Yuan Shao was indecisive and did not adopt.
At the same time, the infighting among Yuan Shao's advisers was very serious, and Xu You's family was arrested for breaking the law, and Yuan Shao did not stop it. Xu You angrily turned to Cao Cao. Subsequently, Xu You suggested that Cao Cao attack Wuchao, burn Yuan Shao's grain and grass, and help Cao Cao defeat Yuan Shao.
After Xu You helped Cao Cao win the Battle of Guandu, he proud of his high merits, despised Cao Cao, and directly called Cao Cao's nickname Ah Qi, which made Cao Cao dissatisfied and killed him.
3. Frustrated
Frustrated at a young age, he became famous and was a very talented strategist. During his period of following Yuan Shao, he suggested that Yuan Shao welcome Emperor Xian and move the capital to Yecheng, so that he could "blackmail the Son of Heaven to order the princes, and the beasts and horses to please the court." Yuan Shao's subordinate Chun Yuqiong and others felt that the Han Dynasty was difficult to revitalize, and took Emperor Xian of Han to Hebei, and Yuan Shao had to be constrained by Emperor Xian of Han at every turn, which would weaken Yuan Shao's power, and Yuan Shao finally chose to give up.
On the eve of the Battle of Guandu, Yuan Shao was given a three-year plan. Cao Cao's strength was inferior to That of Yuan Shao, and he suggested that Yuan Shao use his advantages to fight a protracted war with Cao Cao, constantly sending elite troops to harass and attack Cao Cao's army, which made Cao Cao tired of coping, and in three years, he could drag Cao Cao down. At that time, Yuan Shao poured out of the nest again, but defeated Cao Cao in one fell swoop, but Yuan Shao did not listen, but instead fought a decisive battle with Cao Cao at Guandu. Yuan Shao, due to improper employment and strategic mistakes, eventually made him lose to Cao Cao at Guandu.
After the defeat, Frustrated was captured by the Cao army. Cao Cao admired Frustrated Zhi and wanted to persuade him to surrender for his own use, but Frustrated Zhi was unwilling to surrender, and Cao Cao could only kill him.
Fourth, Zhang Song
Zhang Song was a courtier under Liu Zhang. After Cao Cao defeated Yuan Shao and became the most powerful prince in the world, Liu Zhang felt that it might be Cao Cao who would seize the world in the future, and in order to leave a way back for himself, he sent Zhang Song to visit Emperor Xian of Han and Cao Cao, and wanted to have a good relationship with Cao Cao.
After Zhang Song arrived at Cao Wei, he was snubbed by Cao Cao. Zhang Song's personality is arrogant and debauched, and he also taunts Cao Cao, causing the two to hate each other. During his return to Yizhou, Zhang Song received courtesy from Liu Bei, which made Zhang Song feel that Liu Bei was the lord he wanted to find, so he began to help Liu Bei plot to capture Yizhou. Zhang Song's behavior of eating inside and outside annoyed Liu Zhang, and he was eventually killed by Liu Zhang.