In history, there is actually a lot of controversy about whether Guan Yu should send troops to attack Xiangfan at this time and provoke this war, but I personally think that Guan Yu is okay to fight at this time.

【Causes of the Battle of Xiangfan】

The main reason why Guan Yu launched the Battle of Xiangfan soon after the Battle of Hanzhong was to counter Cao Ren, and by pushing back this battle, the possibility that Guan Yu's battle was a temporary initiative is also very small, and the Battle of Xiangfan is likely to be launched by Guan Yu after a long period of research and careful consideration.

In the "Chronicles of the Three Kingdoms: Emperor Wu Ji" about the battle of Hanzhong, we can see the record of "At the beginning, Cao Ren fought against Guan Yu, Tunfan City", and the previous article also analyzed that at this time Cao Cao sent Cao Ren to crusade against Guan Yu It was indeed a good point in time, but in the end, because of the Wancheng rebellion, Cao Ren delayed the opportunity, but Guan Yu saw that Cao Ren mobilized the army, and he was not a fool, so Guan Yu was ready to fight at that time, but Cao Ren was not ready because of the rear rebellion.

But this does not mean that Cao Ren is easy to bully, after all, Cao Ren's military strength in Xiangfan at that time was still very strong, but Guan Yu beat Cao Ren in this situation, and also committed two military taboos.

The first military taboo is to fight the strong with the weak. At that time, Guan Yu crusaded against Cao Ren, but his own strength and combat power were not as good as Cao Ren, Cao Ren came to Fancheng, not to play swings, he himself came to fight Guan Yu, although there was some loss in the pacification of the Wancheng Rebellion, but the strength is still not to be underestimated, and Guan Yu sent troops north, but because of the threat of Sun Quan, Lu Meng and others, he could not go all out.

The second major military taboo is the uneven road ahead. When Guan Yu attacked Cao Ren, he directly crossed Xiangyang to attack Cao Ren, who was entrenched in the Fancheng area.

We can imagine how Cao Ren felt when he learned that Guan Yu was attacking in this situation, Cao Ren must have felt that Guan Yu was despising himself, so in the end, Cao Ren only left thousands or even more than 10,000 soldiers in Fancheng, and left most of his troops outside Fancheng, putting on a position to fight Guan Yu, from the conventional situation, there is no problem with the decision made by Cao Ren, but judging from the results of the battle, we know that Guan Yu did not plan to fight a regular war with Cao Ren from the beginning.

The key to Guan Yu's final victory was the flood and the water army, he planned to flood Cao Ren's army directly in the Fancheng area from the beginning, so Guan Yu dared to attack the strong with weakness, and dared to cross Xiangyang to fight Fancheng, because the Fancheng area was prepared by Guan Yu from the very beginning, and Guan Yu, who was in a weak position, was able to lead Cao Ren to garrison more soldiers outside the city, it can be said that in the early stage of the battle of Xiangfan, Cao Ren completely followed Guan Yu's rhythm.

There are two main reasons why Cao Ren will be at such a disadvantage in the early stage of the Battle of Xiangfan, one is that Guan Yu is unprepared to fight, and the other is the disadvantage of the navy.

The first reason is very understandable, because Cao Ren pacified the Wancheng Rebellion, he was not ready to go south to crusade against Guan Yu at that time, let alone be prepared to be attacked by Guan Yu, on the contrary, Guan Yu had already made corresponding preparations, and even calculated how he should kill Cao Ren, and Cao Ren knew nothing about it.

The second reason is better understood, Cao Wei Group has always been its shortcomings in water warfare in history, but Guan Yu is also a rare general, obviously born in the north, but very good at leading a water army, at that time if Guan Yu did not have the corresponding surface force, he would not dare to flood, that would flood his own army, and Cao Ren If there is enough water army, then Cao Ren can completely minimize losses.

In the early stage of the battle of Xiangfan, it can be said that Guan Yu was a stage alone, he attacked the strong with weakness, and used the flood to infinitely magnify the shortcomings of Cao Wei's army, and finally achieved brilliant results, almost defeating Cao Ren to the annihilation.

If Guan Yu had temporarily provoked this war, we can imagine that it would have been difficult for him to achieve such results. Guan Yu himself is also a famous general, he will not commit two military taboos at once without preparation, and the time of the Han River surge is also after Guan Yu sent troops, these are difficult to be coincidental.

Since Guan Yu placed the battlefield of the war in the area of Fancheng, where the enemy's base camp was located, the preliminary investigation work must be indispensable, so Guan Yu should have launched the Battle of Xiangfan after planning for a long time, and his preliminary preparations may have been done even before the Battle of Hanzhong ended.

Contacting the rebellion of Jin Yi and others in Xuchang, Guan Yu probably had the idea and preparation of the Northern Expedition earlier, but the situation changed quickly.

Of course, after Liu Bei's victory in the Battle of Hanzhong, it may also have had a great stimulus to Guan Yu, which is probably one of the reasons why Guan Yu finally went north to crusade against Cao Ren.

Back to the original topic, should Guan Yu crusade against Cao Ren at that time? My answer is that Guan Yu has no reason to let go of this opportunity.

First of all, let's look at the choice that Guan Yu faced at that time, Cao Ren had already pressed the border with a large army and was stationed in Fancheng, but because of the fact that Wancheng did not go south for the time being, after Cao Ren was ready in the later period, there was a certain possibility of going south to crusade against Jiangling. (Originally, Cao Ren would definitely go south to attack Guan Yu, but with Cao Cao's withdrawal from Hanzhong, the situation has changed, so it is possible that Cao Ren will change his course and not go south.) ）

And after a long period of preparation, Guan Yu has already prepared a defense against Cao Ren, and even Guan Yu carefully studied the situation in Jingzhou and found an opportunity to defeat or even eliminate Cao Ren, if successful, he can almost wipe out the tens of thousands of elite soldiers under Cao Ren's command.

At this time, Guan Yu had two choices, one was to defend and the other was to attack.

The first is defense, from the consideration of the situation at that time, although Cao Ren has a certain possibility of giving up the attack on Guan Yu, but the initiative is not in Guan Yu's hands, if Cao Cao can't wipe his face, he has to let Cao Ren seize Nanjun to avenge the capture of Hanzhong, Guan Yu has no choice. Guan Yu was ready to defend at that time, and Liu Bei almost returned to Chengdu, even if Cao Ren attacked, Guan Yu could still get the support of Yizhou, so it seems that Cao Ren has little hope of defeating Guan Yu to capture Jiangling and other places, but at the same time, Guan Yu will not be able to flood the Seventh Army, and the possibility of severely invading Cao Ren is also greatly reduced.

After that, it is an attack, if Guan Yu's plan is successful at that time, in the best case, Guan Yu can annihilate tens of thousands of troops under Cao Ren in one fell swoop, seize Xiangyang and Fancheng, and open the road to Xuchang, at worst, Cao Ren's main force is stuck in the city, although it has not been flooded much, but life is not better, and Guan Yu with the water army in his hand wants to fight, want to run, at least after the first battle, Cao Cao and Cao Ren want to counterattack in the short term, because the wreckage after Xiangfan is flooded is still waiting for them to clean up. As for the unsuccessful plan, don't think too much about it, it's much easier to break a vase than to make one.

So why didn't Guan Yu fight Fancheng? He missed this opportunity, next time where would there be such a good opportunity to wipe out Cao Cao's tens of thousands of elite soldiers in one fell swoop.