The Battle of Xiangfan began with Guan Yu's attack on Xiangyang and Fancheng in July 219 and lasted for 5 months until Guan Yu was captured and killed in December 219, liu bei in Yizhou did not send a single soldier to rescue Guan Yu, and Liu Bei's battle of Yiling to avenge Guan Yu was not launched until July 221, which was already a year and a half after Guan Yu was killed.
The whole process of question is very big, why did Liu Bei not support Guan Yu in the 5-month war? Why, a year and a half after Guan Yu was killed, did Liu Bei launch a war to avenge Guan Yu, and the time difference between before and after was so much, for what purpose? Was it that Guan Yu did not pass on military intelligence from the front to Liu Bei during the war?
Guan Yu launched the Battle of Xiangfan
Guan Yu has the right to fake festivals and can go out on behalf of the monarch Liu Bei, but it cannot make decisions on behalf of Liu Bei, which is essentially different, so the Battle of Xiangfan was ordered by Liu Bei to be launched by Guan Yu, and at the same time, Guan Yu's military intelligence in the Battle of Xiangfan should be reported to Liu Bei according to logic.
So how did Guan Yu report the situation to Liu Bei, and how often did it take to report it?
The Battle of Xiangfan took place in Xiangyang City, Hubei Province, Liu Bei was in Chengdu, Sichuan Province, the distance between the two places was almost a thousand kilometers, Guan Yu reported military intelligence to Liu Bei actually had two paths, one was from Xiangyang along the Han River, to Hanzhong controlled by Shu Han, from Xiangyang to Hanzhong the waterway was almost 580 kilometers, and then from Hanzhong to the south, all the way to Chengdu, from Hanzhong to Chengdu there were about 450 kilometers.
Schematic of the Battle of Xiangfan
From Xiangyang to Hanzhong to take the waterway, but also against the river, by boat can only walk up to 10 to 20 kilometers a day, counting up to take a boat to walk for nearly a month, and then from Hanzhong to Chengdu to take the Shu Road, can not ride a horse, can only rely on walking, walk up to 30 kilometers a day, from Hanzhong to Chengdu to walk 15 days.
In this way, Guan Yu sent emissaries to take the Xiangyang-Hanzhong-Chengdu line, and it took a total of 45 days to pass on the information on the front line to Liu Bei.
The second road is from Xiangyang to Jingzhou, the rear of Guan Yu, on horseback, this section of the road is 200 kilometers, and then from Jingzhou by boat, along the Yangtze River upstream into Chongqing, from Jingzhou to Chongqing Yangtze River waterway is almost 700 kilometers, to Chongqing after changing land to take the Sichuan-Chongqing Ancient Road to Chengdu, this section of the road is 300 kilometers.
Map of the situation in the three countries in 219
Riding a horse can walk 60 to 80 kilometers a day, there must be a station in the middle to change horses, it takes about 3 days from Xiangyang to Jingzhou, it takes 35 days to take a boat from Jingzhou to Chongqing, and then it takes more than 10 days to walk from Chongqing to Chengdu, this road adds up, a total of 48 days, Guan Yu can pass on the information of the Xiangfan front to Liu Bei.
It can be seen that the time of these two roads is similar, and the routes are under the control of Liu Bei's forces, and there is basically no problem in transmitting intelligence, but it takes 45 to 48 days to transmit a situation, although this is already fast enough time, but in Liu Bei's hands, there is still a serious lag.
It had been a month and a half since Liu Bei had received Guan Yu's military intelligence on the front line, for example, in August 219, Guan Yu had shocked Huaxia, captured more than 30,000 people from the Forbidden and Seventh Army, and beheaded Pound, a major victory that Liu Bei had received at the end of September or early October.
Guan Yu Wei shook Huaxia
In September 219, Guan Yu continued to fight on the front line, besieging Xiangyang and Fancheng at the same time, controlling the water control of Hanshui, and forming a confrontation with Cao Wei, but Guan Yu failed to expand the results of the battle, and Cao Wei could not lift the siege of Xiangyang and Fancheng for a while.
In October 219, Xu Huang led his army to the outskirts of Fancheng and confronted Guan Yu, at the same time, Sun Quan secretly united with Cao Cao and began a military campaign to sneak into Jingzhou, Lü Meng pretended to be ill, Lu Xun wrote to Guan Yu and complimented Guan Yu, all of which were to confuse Guan Yu, and then Eastern Wu crossed the river in white clothes, let the soldiers hide in boats disguised as merchants, evaded Guan Yu's beacon on the Yangtze River, and uprooted all of Guan Yu's strongholds on the Yangtze River.
Then Lü Meng persuaded Shi Ren and Mi Fang to surrender and captured Gong'an City and Jiangling City, and Lu Xun continued to lead his army to attack all the way, at the same time, Cao Cao shot the news of Sun Quan's sneak attack on Jingzhou with arrows to Guan Yu's camp, Guan Yu began to be suspicious after hearing this, and began to send people back to Jingzhou to inquire about the news, it took 6 to 7 days for the emissaries to come and go, when Guan Yu learned that Jingzhou was lost, it should be after Lü Meng occupied Jiangling City.
Lü Meng crossed the river in white clothes to capture Jingzhou
Then on the front line, Guan Yu lost his defense in the rear, the army was scattered, the soldiers had no intention of fighting, coupled with the fact that the war had lasted for more than three months, the soldiers were also extremely tired, Guan Yu was defeated by Xu Huang and began to withdraw his troops back to Jingzhou, at this time the connection with Liu Bei had been cut off by Eastern Wu, and he just wanted to pass on the military intelligence to Liu Bei's front line, and had lost the opportunity.
Because when Guan Yu had not yet retreated from the Xiangfan front, Eastern Wu had already controlled the core area of Jingzhou, that is, Nan County, Lu Xun continued to fight west to Zigui, which was already the junction of Jingzhou and Yizhou, Guan Yu's way back to Yizhou was actually cut off by Lu Xun, and the time for Guan Yu to retreat back to Jingzhou from the Xiangfan front was no longer than the time when Lu Xun attacked Jingzhou, because many defenders in Jingzhou fled in jingzhou.
At this time, it was already November 219, because Lu Xun led an army to attack the west of Jingzhou, and many soldiers and civilians west of Jingzhou began to flee to Yizhou, so the border generals of Yizhou received the news of the fall of Jingzhou as early as November, which was not sent by Guan Yu, but caused by the attack of the Eastern Wu army.
Guan Yu could not escape
After the Yizhou border general got the news, he would definitely report to Liu Bei in Chengdu, which was about 20 days, so liu bei got the news that Eastern Wu attacked Jingzhou was probably in early December, so why didn't Liu Bei send troops?
Because there was no way to send troops, I didn't know where Guan Yu was, and I didn't know how to save Guan Yu.
Guan Yu's contact with Liu Bei at that time had been severed, and at the same time, Guan Yu was in the process of going south from Xiangfan, the soldiers continued to flee to Lü Meng, Guan Yu could only flee with a few hundred people to Maicheng in the north of Jingzhou, and could not continue to go south, because Guan Yu had no soldiers in his hands, but Guan Yu did not know that Eastern Wu had laid a net of heaven and earth against him, and Eastern Wu had calculated all the routes that Guan Yu might escape, so he waited for the rabbit.
Liu Bei did not know where Guan Yu was
Here Liu Bei got the news of the fall of Jingzhou, but he didn't know where Guan Yu was? Moreover, the Eastern Wu army had already deployed against Yizhou, Liu Bei wanted to launch a military operation, it was impossible to prepare for it in a very short period of time, the war was not to be fought, the soldiers and horses did not move, the grain and grass went first, at this time, only half a year had passed since the two-year-long Battle of Hanzhong, and Yizhou had not yet recovered from extreme consumption.
Liu Bei wanted to send troops to support Jingzhou, must be about Yu news to send troops, but also need time to prepare, in the process of Liu Bei's preparation, the news of Guan Yu's killing came, Sun Quan captured Guan Yu and directly beheaded, and gave Guan Yu's first rank to Cao Cao, such a big thing, Liu Bei will not be unaware, Liu Bei will also send spies to Jingzhou to inquire about the news, when Liu Bei hears that Guan Yu is killed, he will not rush to start a war, he must continue to prepare until he has the strength to start a war.
The two-year Battle of Hanzhong had left the Yizhou soldiers quite tired
Looking at the whole war process, the most critical thing is that after Sun Quan sneaked into Jingzhou, this happened in October 219, even if Guan Yu quickly passed this information to Liu Bei, first of all, he had to ensure the smooth flow of the entire road, in fact, it was a matter of time, as mentioned earlier, it would take 45 to 48 days to deliver the letter to Chengdu, Liu Bei always had to prepare for the army, it took time to collect grain and gather troops, and when Liu Bei was ready, the yellow broccoli was cold.
Therefore, the most crucial thing in the whole Battle of Xiangfan is that the time for the transmission of frontline intelligence is too slow, Liu Bei cannot get the frontline intelligence in time, he can only learn the intelligence of last month this month, a full month and a half late, and when Sun Quan did not sneak attack Jingzhou, Guan Yu has been winning the battle on the Xiangfan front, there is no reason to fight a victorious battle and also to send troops to support it, Liu Bei's Yizhou soldiers originally needed to recuperate, and they really couldn't take it.
Guan Yu was killed
Can't blame Guan Yu for the failure of the Battle of Xiangfan, this is the fault of Guan Yu, Guan Yu is not defenseless Against Sun Quan, the beacon tower and outpost on the Yangtze River are Guan Yu's military facilities to defend Sun Quan, in order to win the Battle of Xiangfan, Guan Yu used all the soldiers who could be sent to the battlefield, Liu Feng and Meng Da refused to support Guan Yu, Guan Yu was also very difficult, and the war was at a critical moment, and could not be easily abandoned.
Guan Yu's Shiren and Mi Fang were two indisputable people, Lü Meng surrendered as soon as he came, causing Guan Yu to lose his rear, and then the whole of Jingzhou was occupied by Eastern Wu, and even Guan Yu himself became a turtle in an urn, naturally there was no way to pass information to Liu Bei, and Liu Bei could not organize an army rescue in a short period of time.