History of Three Kingdoms 111
Why Did Sun Quan want to sneak into Jingzhou
From the time Liu Bei led his troops into Sichuan in 211 AD, Guan Yu was appointed as the later commanderial governor of Xiangyang(襄阳the capital of Jingzhou,occupied by Cao Cao), guarding Jingzhou. During this period Guan Yu also achieved successive victories against Yue Jin（乐进） and Wen Pin(文聘both are mighty Generals under Cao Cao), expanding his territory and strengthening Liu Bei's overall strength.
When Liu Bei captured Chengdu(capital of Yizhou,present day Chengdu) in the summer of 214AD, Guan Yu was given the authority to oversee Jingzhou, formally taking charge of four and a half commanderies, namely Lingling（零陵）, Guiyang（桂阳）, Wuling（武陵）, Changsha（长沙）, and part of Nanjun（南郡）.
Since Nanjun was lent out by Eastern Wu and bordered Jiangxia（江夏） commandery to the east, Guan Yu not only had to fight Cao's army head-on, but also had to carefully manage his relationship with his ally Sun Quan, or else he would be caught in a state of being attacked from both sides.
Guan Yu was a arrogant and tough guy, and often had friction with the Wu army over trivial matters. Fortunately, the Wu general who was stationed at Lukou and responsible for Jingzhou affairs at that time was Lu Su（鲁肃）, who was the initiator of the Sun-Liu alliance. As the initiator of the alliance between Sun and Liu, whenever there was a dispute, Lu Su always looked at the overall situation, appeased Guan Yu with a friendly gesture, and encouraged to maintain the peace between the two sides.
From the perspective of territorial security, Jingzhou was in the upper reaches of Eastern Wu, and its geographical position was very important. Therefore, as early as during the period of Sun Ce（孙策,Sun Quan's brether), he had used all the troops of his state to attack Huang Zu（黄祖,a general under Liu Biao's command,killed Sun Ce and Suan Quan's father), who was stationed in Jiangxia, and achieved a brilliant victory.
After Sun Quan succeeded to the throne, he made three expeditions to the west in the name of avenging his father's death, and eventually killed Huang Zu and seized most of the land in Jiangxia commandery.
Later, Sun Quan moved his capital to Chaisang(柴桑）, and his intention to continue to encroach on Jingzhou was very obvious.
Therefore, after the battle of Red Cliff, Liu Bei's behavior of taking 4 commanderies of Jingzhou, in Liu Bei's own view, this is the right name of fighting against Cao, but Sun Quan's heart has a kind of "the goods already in his bag turned to the enemy's,and his beloved was taken away" sense of sour, jealousy and humiliation.
In the following years, with Liu Bei's "Pissing off Sun Quan 3 times" over the Sichuan issue and the broken marriage with Lady Sun, the heat of the Sun-Liu alliance cooled down rapidly.
Liu Bei even went so far as to display troops on both sides of the Yangtze River to threaten Sun Yu's western expeditionary army by force. Sun Quan, on the other hand, ignored his status as a nobleman and cursed Liu Bei, calling him a "cunning bandit".
At the beginning of 215, Sun Quan demanded the three commanderies in Jingnan, Liu Bei furiously led his troops to Gongan, and ordered Guan Yu to line up in Yiyang to confront Lu Su. Lu Su once again from the general situation of joint resistance to Cao, invited Guan Yu to the single- sword meeting, to avoid the early rupture of this very fragile alliance at this time.
Under Lu Su's mediation, Sun Quan made no further moves, while Liu Bei chose to compromise because Cao Cao had already reached Hanzhong.
Both sides reached the " Covenant of Xiang River"（湘水）, each side got two and a half commanderies in Jingzhou, Guiyang, Changsha and half of Jiangxia went to Sun Quan, Lingling, Wuling and half of Nanjun went to Liu Bei, while the rest - Nanyang(南阳), the northern part of Nanjun and the northern part of Jiangxia - remained in Cao Cao's occupation zone.
In fact, at this time, Lyu Meng had suggested to Sun Quan to find an opportunity to raid Guan Yu and take Jingzhou, but Sun Quan never agreed.
Since Zhou Yu's death, Lu Su, as the leader of the group of military generals from Huai Si(淮泗the area around Huai River and Si River), had influenced Sun Quan's strategic choices and controlled Wu's foreign policy with his outstanding ability and vision.
During this period, Liu Bei occupied Ba commandery and Guan Yu captured Dangyang. Sun Quan captured Zhu Guang in Lujiang and defeated Cao's army and Ruxu. The continuation of the Sun-Liu alliance has indeed weakened Cao Cao's power.
But the good times didn't last long, and huge changes came suddenly in 217 AD. Lu Su, the last strategic master of Jiangdong who had made the unification of the whole country as his goal, died of illness in Lukou, and Sun Quan was immersed in great grief. But after the tears were shed, the only thing that lingered in Sun Quan's mind was the helplessness of not being able to conquer Hefei for many years, and Zhang Liao's(张辽) roar in Xiaoyao Ford(逍遥津).
Guan Yu, from a guerrilla leader with only a few thousand soldiers at the time of the "Blocking the Northern Way", in just a few years, he " drowned seven armies", "Shocking the whole China" became the "master of War". Liu Bei, from a vagabond with no base, became the powerful Prince of Hanzhong, spanning the provinces of Jing and Yi.
Sun Quan witnessed Liu Bei's rising, and his ambition to go north gradually turned into morbid jealousy and deep grudge against Liu Bei along with the day-to-day self-doubt.
After Lu Su's death, Sun Quan ordered Lyu Meng to station at Lukou, commanding all the troops left behind by Lu Su, and appointed him as the governor of Hanchang(汉昌,a new conmandery set by Sun Quan,between Changsha and Jiangxia), overseeing the affairs of Jingzhou.
As soon as Lyu Meng arrived, he established favor and reward internally, befriended Guan Yu externally and behaved very attentively, but secretly, he had been plotting with Sun Quan to raid the whole Jingzhou.
Before Guan Yu set out on the Northern Expedition, Sun Quan had sent an emissary to Jiangling to ask for his son's hand in marriage to Guan Yu's daughter.
Guan Yu thought he was just a general under Liu Bei, and did not match Sun Quan's position as the Lord of Eastern Wu.
Moreover, Sun Quan and Liu Bei had a marriage relationship before, if Sun Quan sincerely wanted the two sides to get married again, he should have sent someone to ask Liu Bei's opinion first.
Now he directly proposed marriage to Guan Yu, there is a suspicion of intentionally attracting Guan Yu, and even provoke the relationship between Liu Bei and Guan Yu, which is typical of no good intentions.
Therefore, Guan Yu flatly rejected the offer and even insulted Sun Quan's messenger in public.
When the news came back to Jiangdong, Sun Quan was angry at first, then he quickly calmed down.
He was using this move to tell the history of the world this, " You see! I have given Guan Yu a chance, but he doesn't treasure it, it's Guan Yu who doesn't know how to appreciate his honor first, you can't blame me!"
Thinking like this, Sun Quan seems to have a few more peace in his heart. But how many people can understand Sun Quan's peace in his heart when the ink is not yet dry on the " Covenant of Xiang River"?
Therefore, whenever people think of the greedy eyes of Sun Quan looking at Jiangling, this picture will always come to mind: in a dark night with howling wind and torrential rain,and the moon have no light, and a dirty hand reaches out to the red and wet begonias.