This question is very interesting.

But it’s actually easy to understand.

Liu Bei indeed only borrowed one Nanjun from Sun Quan, but Sun Quan asked Liu Bei to return the entire Jingzhou. Why? There is no record in the Chronicle of the Three Kingdoms, but we can reasonably speculate that Liu Bei must have made a promise to Sun Quan, and Sun Quan lent Nanjun to him.

In layman's terms, Nanjun was the capital lent by Sun Quan. The remaining counties in Jingzhou are the ones Liu Bei promised. You will have to pay back the principal and interest in the future.

We must first figure out why Liu Bei borrowed Jingzhou.

In 208 AD, the allied forces of Sun and Liu burned Chibi, defeated Cao's troops, and pursued them all the way to Nanjun. Then the troops were divided into two groups. Zhou Yu attacked Nanjun, and Zhang Fei led 2,000 people to help. Liu Bei led the main force to pacify the four counties south of the Yangtze River in Jingzhou. It occupies the four counties of Lingling, Guiyang, Changsha and Wuling. The First Lord Biao Qi was appointed governor of Jingzhou, and he also marched south to four counties. Jin Xuan, the prefect of Wuling, Han Xuan, the prefect of Changsha, Zhao Fan, the prefect of Guiyang, and Liu Du, the prefect of Lingling, all surrendered.

It can be seen from this that after the Battle of Chibi, most of Jingzhou was occupied by Liu Bei, and Liu Qi occupied one Jiangxia County. Sun Quan's army only occupied half of Nanjun! Qi died of illness, and the people elected him as the herdsman of Jingzhou and in charge of public security. If Quan is slightly afraid of it, it will be good to enter the sister. The First Lord came to the capital to see Quan and to prepare for his kindness.

After Liu Qi died of illness, Liu Bei became the herdsman of Jingzhou. It can be said that Jingzhou originally belonged to Liu Bei, so how do we start talking about "borrowing Jingzhou"?

In fact, it lies in the words "The First Lord came to the capital to see his power and prepare for his kindness".

Sun Quan married his younger sister to Liu Bei. Liu Bei personally went to Soochow to meet with Sun Quan. The two chatted happily.

What exactly is it?

It is impossible for two men with great talents to discuss their parents' personal differences. It must be discussing world affairs. Discuss how to divide the world.

Liu Bei took the opportunity to propose a deal to Sun Quan, which was to borrow Nanjun. Of course it's not for nothing, the reward is the entire Jingzhou. I think Liu Bei said this, uncle Sun Quan, can you give me your little Nanjun so that my brother can settle down temporarily? When my brothers capture Yizhou, I will give you the entire Jingzhou!

When Sun Quan heard this, he thought this was a good deal! Dry!

So Nanjun was given to Liu Bei. This is the so-called borrowing from Jingzhou.

When Liu Bei really occupied Yizhou, Sun Quan happily sent Zhuge Jin to claim Jingzhou. Liu Bei pushed back and then started to lie again, saying that brother, I was preparing to attack Liangzhou, and when it was captured, Liangzhou gave the entire Jingzhou to Soochow. It was the year Liu Bei settled in Shu. In order to prepare for the victory of Yizhou, he ordered Zhuge Jin to ask for the counties in Jingzhou. Bei refused and said: "My plan for Liangzhou and the determination of Liangzhou are based on Jingzhou and Wu'er." Quan said: "This is false but not counter-intuitive. It is just an attempt to usher in the new year with empty words." "Three Kingdoms Chronicles of Wu Zhu Zhu"

When Sun Quan heard this, his lungs exploded with anger. This damn person is acting like a rogue, "You can never repay what you borrow! You are just relying on sweet words to delay the period!" So he sent troops to sneak attacks on the three counties of Changsha, Wuling and Guiyang in Jingzhou.

When Liu Bei saw that Sun Quan dared to take action, he simply kicked his nose in the face. Guan Yu was immediately ordered to send 30,000 troops to Yiyang. He led an army of 50,000 to the police station. A total of 80,000 troops wanted to fight Sun Quan to the death and vowed to destroy Soochow.

At this time, Sun Quan only had 30,000 people in Jingzhou. At an absolute disadvantage in terms of numbers. Once a fight breaks out, you will suffer big losses.

As a result, Sun Quan was very lucky, and Cao Cao suddenly attacked Hanzhong, endangering Shu. Liu Bei had no choice but to negotiate a peace with Sun Quan and divide Jingzhou equally with the Xiangjiang River as the boundary.

After all, Liu Bei and Sun Quan were plotting against each other, which was shameless.

Liu Bei wanted to defraud Nanjun, so he lied that he wanted to send Jingzhou. Sun Quan wanted the whole of Jingzhou, so he lent Nanjun to Liu Bei.