What caused Cao Cao to lose his position as ally?
The Romance of the Three Kingdoms was written by Luo Guanzhong at the end of the Yuan Dynasty and the beginning of the Ming Dynasty, describing the story from the chaotic battle of the masses at the end of the Eastern Han Dynasty, the establishment of the Three Kingdoms of Wei, Shu and Wu, to the unification of Sima Yan and the establishment of the Jin Dynasty.

Among them, the fifth time: "Issuing Corrections to the Towns should be Cao Gong Breaking the Officers and Soldiers three Ying Battle Lü Bu" is about cao Cao's failure to assassinate Dong Zhuo, fleeing back to his hometown, issuing corrections, planting the "loyalty and righteousness" banner, forming an alliance with allies, and attacking Dong Zhuo. In this alliance, Cao Cao was the core figure and played a key role, and the leader of the alliance was indeed Yuan Shao, what caused Cao Cao to lose the position of the leader of the alliance? We look for the answer in this description of Cao Cao.
When asking for help from Wei Hong, Wei Hong said: "I have a long heart, and I hate that I have not met the hero's ear." Since Meng De has great ambitions, he is willing to help his family. It shows that Wei Hong recognized Cao Cao as a hero and worth following, and would only give his entire family property to support Cao Cao, including his own life.
After issuing edicts, planting the banner of "loyalty and righteousness", and making a proclamation to the world, seventeen town princes responded. It shows that Cao Cao has some popularity.
When Cao Slaughtered Cattle and Slaughtered Horses, assembled the princes, and discussed the strategy of entering the army, Wang Kuang proposed to choose the lord of the alliance, and Cao Cao proposed that "the third duke of the fourth generation of Yuan Benchu, the former official of Menduo, and the descendant of the famous minister of the Han Dynasty, can be the lord of the alliance." And "everyone knows it has to be the beginning." It was said that the choice of the leader of the alliance was not proposed by Cao Cao, but after Wang Kuang proposed it, Cao Cao immediately recommended Yuan Shao, and everyone recognized it.
Yuan Shao looked down on Guan Yu, if it were not for Cao Cao's strong advocacy, Guan Yu would not necessarily have the opportunity to "warm wine and cut Huaxiong", and then spoke for Zhang Fei to provoke Yuan Shao, said the words of resignation, and finally had to appease Yuan Shao and then "secretly let people drink cattle to comfort the three people". It can be seen that compared with Yuan Shao, Cao Cao is more sleek in his handling of things and has a stronger ability to handle things.
When confronting Dong Zhuo Lübu, Cao Cao proposed to divide his troops to meet him. It shows that he has the ability to lead soldiers to fight.
From the above points, it can be concluded that for this alliance, the initiator is Cao Cao; the investor is Cao Cao; and the people are also gathered by Cao Cao. The goal is to get rid of Dong Zhuo, and Cao Cao, who has the ability, status, and smoothness, is the best candidate for the alliance, but why was he not elected? Is it about seniority ranking status, or ulterior motives! Personally, I think there are several reasons for this:
One is the accident. Why is it an accident? Begin to "slaughter cattle and horses, assemble the princes, and discuss the strategy of entering the army." At this time, Cao Cao treated him as his master (ally), but Wang Kuang of Taishou suddenly proposed: "Now that we are serving the great righteousness, we will establish an alliance lord; the people will listen to the restraints, and then march into the army." "Disrupted Cao Cao's plans." Hindered by his face, he retreated to the second place, and promoted Yuan Shao (Cao Cao knew Yuan Shao's ability and was not suitable to be the leader of the alliance), "Yu Jie knew that he had to be the original", and also had two meanings: on seniority, "Yuan Benchu's fourth three dukes, menduo old officials, and the descendants of the famous han dynasty"; then there was the candidate proposed by Cao Cao, and everyone only followed Cao Cao's decision.
Second, Cao Cao did not want to be. Pushing out Yuan Shao in the open, while his own dark control, Yuan Shao is actually Cao Cao's shield.
The third is that Cao Cao is in the next big game. Cao Cao understood that the alliance between the various princes was not strong, and each had different intentions, so he waited on the sidelines and waited for a suitable node to strike in order to obtain the greatest benefit.
Without referring to the later chapters, what do you think is the reason?