History of Three Kingdoms - Chapter 110
How mighty is Xu Huang?
In October 219 AD, Sun Quan sent a messenger to Cao Cao with a secret letter that said, "I intend to send troops westward to raid Guan Yu. Jiangling and Gongan are Guan Yu's key locations. Once Guan Yu loses these two cities, he will surely flee and the siege of Fancheng will lift itself without rescue. Please, Your Grace, don't let the news leak out to let Guan Yu be on guard! "
When Cao Cao saw the letter, he summoned his ministers to ask for advice, and they all agreed that it should be kept secret.
Dong Zhao（董昭）, Cao Cao's main strategist, advised Cao Cao:
"Military matters should be handled on an ad hoc basis. We only need to consider what is best for us, and it's none of our business whether or not Sun Quan succeeds in his surprise attack.
If we take the initiative to leak out the news and Guan Yu doesn't retreat after hearing about it, Sun Quan will be able to succeed in his raid just the same, so it doesn't matter if we keep it a secret or not.
If Guan Yu chooses to retreat to protect himself, the siege of Fancheng will be lifted immediately, and the two families will fight to the death under the city of Jiangling, so we can reap the benefits.
In addition, Cao Ren and Man Chong and other people in the city, if they know that Sun Quan is about to make a move, the will to resist will be stronger.
Therefore, I suggest that we promise to keep Sun Quan's secret on the surface, but secretly leak the information to Guan Yu.
I surmise that Guan Yu has a strong character, and relying on the strong defenses of Jiangling and Gongan, he will not easily retreat."
Cao Cao deeply agreed with Dong Zhao's opinion, so he ordered Sun Quan's secret letter to be sent to the front line, and had Xu Huang copy multiple copies and shoot them into Fancheng and Guan Yu's battalion outside the city with his arrows.
When Cao Ren and the others saw the letter, their fighting spirit was indeed increased, while most of the families of the soldiers of the Shu army were living in the city of Jiangling, so the army's morale was greatly affected, and Guan Yu was caught in a state of indecision.
By this time, the various reinforcements sent by Cao Cao had basically arrived, and the waters were beginning to recede. Xu Huang keenly seized the opportunity and made a prompt decision to start an attack on the besieging Shu army.
At that time, Guan Yu's main force was stationed in Weitou（围头）, and a separate force was stationed in Sizhong（四冢）. Xu Huang threatened to attack Weitou, but made a surprise raid on Sizhong. Fearing that this force would be wiped out, Guan Yu led 5,000 infantry and cavalry to Sizhong to confront Xu Huang.
Guan Yu and Xu Huang are both from Hedong commandery(present day Shanxi Province), so when Guan Yu was temporarily under Cao Cao's command 20 years ago, he formed a deep friendship with Xu Huang.
Before the battle, the two men steered their horses in front of the formation and conversed from afar, but only about family affairs, not military matters.
After chatting like this for a while, Xu Huang suddenly dismounted and announced the military order, "The person who gets Guan Yu's head will be rewarded with a thousand pounds of gold!" Guan Yu was shocked to hear this and said to Xu Huang, "Big brother! What are you talking about?" Xu Huang replied, "I'm sorry,It's a national business!"
A melee ensued between the two armies. Guan Yu was not prepared enough and was therefore defeated by Xu Huang. Seeing Guan Yu retreating, Xu Huang immediately led his troops to pursue him and followed him closely, charging into Guan Yu's battalion.
Regarding the strict governance of the army, Guan Yu's battalion, the internal and external defenses were built very tightly. Not only were deep trenches dug on the outside, but as many as ten barricades were constructed.
Originally, it would have been very difficult to make a strong frontal attack from outside the battalion , but now Xu Huang took advantage of the Shu army being in a state of chaos, chased after them, drove straight in, and attacked them from the inside to the outside, breaking the Shu army in one fell swoop. Many soldiers were driven into the Han River by Xu Huang and drowned.
The Wei army won a decisive victory, Hu Xiu(胡修）, the provincial governor of Jingzhou, and Fu Fang（傅方）, the governor of Nanyang（南阳）, who had previously surrendered to Guan Yu, were both killed.
Guan Yu withdrew his defeated troops to the Han River, Cao Ren and Man Chong, who had been besieged for four months, escaped successfully.
When the news of the victory reached the Mobei, Cao Cao's heart was filled with joy beyond words, and he gave Xu Huang the highest praise:
"Guan Yu's trenches and barricades were as many as a dozen , but Xu Huuang accomplished it in a single battle! I've been fighting for more than 30 years, and I've never seen a battle in which someone takes the initiative to rush into the enemy's encirclement, so today he really blew my mind! General Xu Huang's feats far surpass those of Sun Wu（孙武the author of Sun Tzu's Art of War） and Sima Rangju（司马穰苴Famous military strategist of the late Spring and Autumn period in China）！"
Though Xu Huang has relieved the siege of Fancheng with this great victory, Xiangyang City on the south bank of the Han River is still in a situation of being surrounded. Because Guan Yu's navy still has absolute dominance over the Han River, Xu Huang can only look at the water and sigh,without any idea.
After this battle, all of Cao Cao's rescue operations come to an end, and the fall of Xiangyang is just a matter of time.
Now that Cao Ren has been rescued, Lyu Chang, the General of Crossing the sea,who stayed in Xiangyang, there is no one who cares about him either died or surrendered.
That month Zhao Yan（赵俨,an important minister of Wei,a famous scholar) stayed behind to continue assisting Cao Ren, while Xu Huang was transferred back to Mobei. Cao Cao personally went four kilometers out of the city to welcome him and hosted a banquet to celebrate his success. Cao Cao visited all the armies and when he saw Xu Huang's army in perfect order, he praised him, "General ,you truly have style of Zhou Yafu（周亚夫,a famous general in Western Han,pacified the rebellion of 7 Princes)! "
Objectively speaking, without this secret letter from Sun Quan, the probability is that Xu Huang would still have defeated Guan Yu. After all, after the rainy season, Guan Yu lost the advantage of being good at water warfare. Moreover, Xu Huang had enough troops, while Guan Yu had no one to support him.
Without Sun Quan's subsequent back-stabbing, Liu Bei would have owned the entire Nanjun commandery after Guan Yu captured Xiangyang. Cao and Liu would separately rule the northern part of Jingzhou dividing by the Han River.
Judging from the eagerness to move Xu Huang back, Cao Cao has mentally accepted this as well. Zhuge Liang's Longzhong strategy "across the Jingzhou, Yizhou, United Sun Quan to the east, when the world has changed, sent troops from both sides, then the supremacy can be accomplished, the Han dynasty can rise," the ambitious wish, may not be impossible to realize.
Because nearly 3 months from now, the biggest change in the northern central plains will come! At that time, Liu Bei and Guan Yu, with the prestige of their great victory, will attack from both sides, by land and water. Sun Quan will attack Hefei with all his troops, how will the chaotic Wei be able to resist?"
This was the perfect and only opportunity for Sun and Liu to subvert Wei and take control of their own destiny!
What if, Guan Yu hadn't sent two clowns to guard Jiangling and Gongan?
What if Lyu Meng(吕蒙a mighty General of Eastern Wu) had gotten sick a month earlier?
If Lu Su（鲁肃a great strategy Master of Eastern Wu) hadn't passed away at the age of only 46?
If Sun Quan had even 1/10 th of the ambition of his father and big brother?
But history has no what ifs, at this time Lyu Meng was standing on the south bank of the Yangtze River, the north wind blew the corners of his white clothes, gently rattling in the dim twilight. The fast ships are just like arrows leaving the strings, speeding towards the west!