Cao Rui

The choice of empress had been an immediate issue after Cao Pi became emperor in 220.

Lady Zhen was his wife, but by this point had long lost favor due to a variety of reasons including the struggle she had with a favorite concubine of Cao's, Guo Nüwang.

Lady Guo used the unlikely possibility that Zhen's son Cao Rui might be biologically Yuan Xi's son to full advantage in creating conflicts between Cao Pi and Lady Zhen.

Cao therefore had refused to summon Lady Zhen to Luoyang after he ascended the throne but instead ordered her to remain at Yecheng, which caused Lady Zhen to be resentful.

When words of her resentment reached Cao, he became angry and forced her to commit suicide.

In 222, Cao had created Consort Guo empress.

Empress Guo, however, is without make issue.

Lady Zhen's son Cao Rui is the oldest of Cao Pi's sons, but because she had been put to death and because of Cao Pi's lingering doubt as to his paternity, has not been created crown prince.

but instead had been made only the Prince of Pingyuan following Cao Pi's ascension.

Cao Pi, however, does not appear to have seriously considered any other son as heir.

(It might have been because the other sons were all significantly younger, although their ages were not recorded in history.)

In the summer of 226, when Cao Pi is seriously ill, he finally creates Prince Rui crown prince.

On his deathbed, he entrusts his successor to the care of Cao Zhen, Chen Qun, and Sima Yi.

Following Cao Pi's death, Prince Rui ascends the throne at the young age of twenty-one.

Sun Quan himself is, however, equally unsuccessful in efforts to make major attacks on Wei.

After Cao Pi's death in 226, for example, Sun Quan launches an attack on Wei's Jiangxia prefecture (in present-day Xiaogan, Hubei) but is forced to withdraw as soon as Wei reinforcements arrive.

It had been commonly expected when Cao Rui became emperor that his wife, Princess Yu, would be created empress, but she was not.

Rather, he creates a favorite concubine, Consort Mao, empress in 227.

Princess Yu is exiled back to their original palace.

He loves Empress Mao dearly, and a number of her relatives, including her father and brother, become honored officials (but without actual powers).

The one major victory that Wu has over Wei during this period comes in 228, when, with Sun Quan's approval, his general Zhou Fang pretends to surrender to Wei after pretending to have been punished repeatedly by Sun Quan.

This gambit deceives the Wei general Cao Xiu, who leads a large army south to support Zhou Fang.

According to legend, Cao Xiu did not believe Zhou Fang at first.

Zhou Fang cut off his famous locks of hair to prove his "loyalty".

In any case, Zhou Fang knew the territory, so he started to lead Cao Xiu into a clearing, where Cao could set up camp.

However, before they left, Cao Xiu had been advised not to trust Zhou Fang by one of his advisers, Jia Kui.

Cao Xiu had not heeded his words; however, and had not only bought Zhou Fang's ploy, but removed Jia Kui from the campaign and decided to march with seventy thousand troops.

On the way to the designated camping area, Cao Xiu is ambushed as planned.

Unable to gain the upper hand in battle, he thus retreats to make camp at Shiting (present-day Qianshan County, Anhui).

However, the camp is disturbed in the middle of night, and the soldiers run away in disarray.

Many sets of armor and carts of supplies are abandoned.

Cao Xiu sends in a memorial acknowledging his fault.

Many of his men are killed.

When he looks around for Zhou Fang, Zhou is nowhere to be found; he now realizes knew he had been duped.

Too ashamed to turn back, and believing that he has more troops and supplies than the enemy, he chooses to engage Lu Xun's army.

Lu Xun personally leads the central force and orders Zhu Huan and Quan Cong to take the left and right flanks.

The three armies advance simultaneously, and decisively take on Cao Xiu's ambushing troops.

Following that, the Wu troops pursue the fleeing Cao army until they reach Jiashi, where they annihilate some ten thousand men and win over ten thousand spoils of war; in addition, all of the Wei army's equipment and weaponry are looted.

Lu Xun regroups his men; and when he passes by Wuchang, Sun Quan instructs his attendants to shield Lu Xun with his own canopy when entering and leaving the palace doors.

Sun Quan bestows upon Lu Xun as reward precious items of the finest grade, honors received by no one else in this era.

Cao Xiu had barely escaped the battlefield with his life; he will die a few months later of an ulcer on his back, even after having been pardoned by the Emperor of Wei, Cao Rui.

Jia Kui, who had come along with Cao Xiu, had helped Cao retreat from the ambush.

For this, Jia Kui is highly praised by Cao Rui himself, and given many promotions.

He will live the last years of his life in happiness.

Sun Quan declares himself emperor in 229, an act that almost damages the alliance with Shu, as many Shu officials see this as a sign of betrayal of the Han Dynasty—to which Shu claims to be the legitimate successor.

However, Zhuge Liang opposes ending the alliance and in fact confirms it with a formal treaty later this year, in which the two states pledge to support each other and divide Wei equally if they can conquer it.

Later this year, he moves his capital from Wuchang (in present-day Ezhou, Hubei) to …

…Jianye, leaving his crown prince Sun Deng, assisted by Lu Xun, in charge of the western empire.

Kushan emperor Vasudeva I is recorded in the Chinese historical chronicle Sanguozhi to have sent tribute to the Chinese emperor Cao Rui of the Wei in 229 CE (third year of Taihe): "The king of the Da Yuezhi, Bodiao (Vāsudeva), sent his envoy to present tribute and His Majesty granted him a title of "King of the Da Yuezhi Intimate with Wei.” He is the last Kushan ruler to be mentioned in Chinese sources.

His rule corresponds to the retreat of Chinese power from Central Asia, and it is thought that Vasudeva may have filled the power vacuum in this area.

The great expansion of the Dharmaguptaka Buddhist group in Central Asia during this period has also been related to this event.

The first sign of the deterioration of Sun Quan's reign occurs in 230, when he sends his generals Wei Wen and Zhuge Zhi with a navy of ten thousand into the East China Sea to seek the legendary islands of Yizhou and Danzhou to seek to conquer them, despite the strenuous opposition of Lu Xun and Quan Cong.

The Wu navy is not able to locate Danzhou but locates Yizhou (Taiwan), and returns in 231 after capturing several thousand men—but only after eighty to ninety percent of the navy has died from illness.

Instead of seeing his own fault in this venture, Sun Quan simply executes Wei Wen and Zhuge Zhi.

Gongsun Yuan's repeated communication with and sales of horses to Eastern Wu angers Cao Rui, who in 232 orders his generals Tian Yu and Wang Xiong to attack Liaodong against the advice of Jiang Ji; the attacks are unsuccessful, although Tian is able to intercept the Eastern Wu horse-buying fleet and destroy it.

After the incident, although Gongsun formally maintains vassalage to Cao Wei, the relationship is damaged.