In the later years of Emperor Jin Wudi's reign, the issue of succession became a key matter. Since Cao Pi, the Wei Emperor, established the "Nine-Rank System," over the years, the aristocratic families have not only become a powerful force politically but also the most critical factor in the upper ruling class for matrimonial alliances. Prestige and family background became the first choice for high-ranking families to form matrimonial ties. Following Sima Shi marrying the daughter of Yang from the famous Confucian Cai Yong’s family and Sima Zhao marrying Wang, the eldest daughter of the renowned Confucian scholar Wang Su from the Wei Dynasty, Sima Yan married a woman from the prestigious Yang family of Hongnong Hanyin. Emperor Jin Wudi was described as having long hair that reached the ground and an imposing appearance, while Empress Yang Yan was "intelligent from a young age, good at writing, and possessed beautiful features." Such a strong combination produced three sons and three daughters, all of whom were fine except for Crown Prince Sima Zhong, who was born foolish with slightly higher intelligence than a fool (Emperor Jin Wudi's eldest son Sima Gui had died in infancy).
From a medical and genetic perspective, both Sima Yan and Yang Yan were healthy, and Sima Zhong, Emperor Hui of Jin, had one son and four daughters, all of whom were intelligent. The low IQ of Emperor Hui might be due to his mother being pregnant for too long or the midwife being too slow when pulling him out of the birth canal, causing injury to his head.
Although emperors and their sons do not live together like ordinary fathers and sons, Sima Yan knew well that Crown Prince Sima Zhong had some mental issues. His foolish behavior and vacant gaze were evident to anyone during their meetings. Sima Yan did not lack for sons; he had twenty-six sons in total. Among them, three kings involved in the "Rebellion of the Eight Kings" (Chu King Sima Wei, Changsha King Sima Yi, and Chengdu King Sima Ying) as well as Emperor Huai of Jin, Sima Chi, were handsome and highly intelligent. Emperor Wu and Empress Yang had a good relationship, and after returning to the palace, Emperor Wu expressed that the crown prince was not fit to inherit the throne and wanted to replace him with another son. Empress Yang was greatly shocked and advised: "The heir should be chosen based on lineage and seniority, not talent. How can this be changed!" Although her words were reasonable, allowing her foolish son to sit on the throne was shortsighted without any foresight. Emperor Wu, who easily swayed by others' opinions, decided against making more trouble after being persuaded by the empress. Additionally, Crown Prince Sima Zhong's son, Sima Yu, was exceptionally clever and deeply favored by Emperor Wu, so the idea of replacing the crown prince gradually faded.
Before Crown Prince Sima Zhong's wedding, Emperor Wu wanted to arrange a marriage with the daughter of Wei Guan, known for her noble lineage, many children, beauty, and fair complexion. However, Empress Yang and the wife of Minister Jia Chong, Lady Guo, had a good relationship, and Empress Yang privately received many rare treasures from Lady Guo. As a result, she praised Jia Nanfeng as generous and virtuous, recommending her as the crown prince's consort. Once again, Emperor Wu was misled by the empress, welcoming the short, fat, dark, and ugly Jia Nanfeng into the palace to marry Crown Prince Sima Zhong. This "ugly and treacherous" woman would become the biggest time bomb to destroy the Western Jin Dynasty.
Originally, Jia Nanfeng's younger sister, Jia Wu, was supposed to be the crown prince's consort. Jia Wu was twelve years old, one year younger than Crown Prince Sima Zhong. Being from the Jia family, she also had bad hair and clothing coordination, and at twelve years old, she was "ugly, short, black, and too small to wear clothes properly." Therefore, Empress Yang and Lady Guo decided to marry fifteen-year-old Jia Nanfeng to Crown Prince Sima Zhong instead. Jia Nanfeng was "jealous and full of deceit," causing Crown Prince Sima Zhong to fear and be confused by her, with few concubines able to serve him. Moreover, Jia Nanfeng was cruel by nature, personally killing several serving girls. Once, upon discovering a palace maid secretly pregnant with Crown Prince Sima Zhong's child, she angrily stabbed her with a sharp spear, causing the already formed fetus to fall dead. Upon hearing the news, Emperor Wu was furious and decided to imprison her in Jin Yong City (a place used by the Jin Dynasty to confine deposed concubines, empresses, and royal family members). At the time, Empress Yang (Yang Zhi, the cousin of Yang Yan. Before dying, Yang Yan entrusted her affairs to Emperor Wu, asking him to marry her cousin, "The emperor wept and agreed.") recommended leniency because Jia Gong (Jia Nanfeng's father Jia Chong) had great merit for the state (helping the Sima family overthrow the Wei Dynasty). His family, even if guilty, should be pardoned multiple times, let alone his own daughter. Now, Consort Jia was young and prone to jealousy, so it was inappropriate to cover her minor offenses with her father's great virtues. Hearing this, Emperor Wu calmed down. However, as the current empress, although only about ten years older than Consort Jia, Empress Yang repeatedly warned this "daughter-in-law" to restrain her actions and behave properly. Consort Jia did not know that Empress Yang had saved her behind the scenes and instead believed Empress Yang was speaking ill of her to Emperor Wu, thus harboring resentment towards her "mother-in-law."
In the later years of Emperor Wu's reign, indulgence in wine and women severely affected his health, causing deep concern among his ministers. The minister He Qiao subtly advised Emperor Wu, saying: "The crown prince has a simple and ancient style, but in these degenerate times, there are many pretenders. I fear he may not be able to handle your household affairs." Sima Yan remained silent. The elder statesman Wei Gun once took advantage of a banquet's drunken atmosphere, stroking the imperial throne and saying to Emperor Wu: "This seat is regrettable."
Emperor Wu was uneasy. One day, he gathered all the officials from the Eastern Palace to a banquet and gave them sealed documents to test the crown prince's ability to handle official business without assistance from palace officials. He sent messengers to wait outside for the crown prince's replies. "The crown prince's consort was extremely fearful and hired someone else to answer. The answers contained many classical references." Jia Nanfeng was terrified; if her husband was deposed, she would go from being the crown princess to just another prince's consort, and after the new emperor ascended the throne, she would surely be at the mercy of others. She had married this foolish man precisely to secure the position of empress, and if the "exam" went poorly, everything would be lost! In haste, they found a pedantic scholar to ghostwrite the responses, filling the documents with classical references and idioms. Fortunately, there was a clever eunuch named Zhang Hong inside the palace who advised: "It is widely known that the crown prince dislikes studying. If the response cites numerous classical texts, the emperor will surely see through it and blame those responsible for helping him. It would be better to address the matters directly and write clear judgments."
Jia Nanfeng was delighted and told Zhang Hong: "Please write it well for me, and I will ensure your wealth and honor in the future."
Zhang Hong, with his modest talents, drafted the document and had the crown prince copy it verbatim. The low-IQ crown prince then dispatched the waiting messenger to deliver the reply during the banquet where Emperor Wu was entertaining the eastern palace officials and court ministers.
Upon reviewing it, Emperor Wu was pleased. He first showed the document to Grand Tutor Wei Gun. Originally expecting little from Crown Prince Sima Zhong, Emperor Wu was pleasantly surprised to see his son's handwritten judgment clear and appropriate. Happy, he handed the document to Wei Gun, subtly conveying the message: "You often say the crown prince is not fit to succeed, but look, he's not bad, is he?" Everyone realized that Wei Gun had previously criticized the crown prince, and they all cheered "Long Live the Emperor!" Thus, the Jia family secretly marked Wei Gun for retribution later.
Of course, various historical records portray Jia Nanfeng as an ugly and cunning woman who relied entirely on deception to ultimately make the foolish Sima Zhong become Emperor Hui of Jin. Based on my estimation, the final decision was still made by Emperor Wu himself. What he valued most was actually Sima Yu, the son of Emperor Hui.
Sima Yu's mother, Xie Jiu, was described as wise and upright. Selected to join Emperor Wu's harem as a talented woman, she had been "tasted" by Emperor Sima Yan. When Sima Zhong was ten and became crown prince, selecting a suitable crown princess became a major event. "Emperor Wu considered the crown prince still young and unaware of marital matters, so he sent her to the eastern palace to serve." This sentence reveals that Emperor Wu had used this beautiful talented woman multiple times, finding her intelligent and considerate, sending her to teach his foolish son about sex and how to interact with women. "(Xie Jiaren) thus became pregnant." After Jia Nanfeng entered the palace, she could arbitrarily kill other concubines in the crown prince's palace but dared not harm Xie Jiaren. Xie Jiaren knew Jia Nanfeng's extreme jealousy, "so she requested to return to the western palace and gave birth to Crown Prince Minhuai (Sima Yu)." A few years later, the foolish crown prince entered the palace to pay respects to his father, seeing a cute three- or four-year-old chubby boy playing with several princes. Approaching, he grabbed the child's hand and laughed foolishly. From afar, Emperor Wu saw this and approached, telling Sima Zhong: "This is your son." Sima Zhong, not understanding, could only kneel and thank his father.
Thus, one can imagine that Sima Yu, this beautiful child, might also be Emperor Wu's bloodline. Although Xie Jiaren and Sima Zhong had shared intimacy multiple times, the possibility of a twelve- or thirteen-year-old boy impregnating someone was relatively low. Emperor Wu merely used his foolish son as a transition, hoping deep down that his younger son Sima Yu would eventually ascend to the throne as the crown grandson. However, what Emperor Wu did not anticipate was that Crown Princess Jia Nanfeng was too cruel, the court ministers were incompetent, and his Sima descendants were unworthy. Consequently, upon his death, not only did the Jin Dynasty quickly disintegrate, but his beloved crown grandson (or prince) ultimately fell victim to Jia Nanfeng's blade.
Besides having numerous sons, Emperor Wu also had a "virtuous and close" younger brother—Prince Qi, Sima You.
Prince Qi, Sima You, was originally Emperor Wu Sima Yan's younger brother, sharing the same parents and thus the closest blood relative. Initially, after the cunning veteran Sima Yi passed away, his eldest son Sima Shi continued to hold power in the Wei Dynasty, serving as regent under the title of Grand General. Seeing his older brother without a son, Sima Zhao adopted his second son, Sima You, as Sima Shi's son. Sima Shi expanded the Sima family's power and achievements continuously, dying in the army during the campaign to suppress Wen Qin in Huainan at the age of forty-eight. After the establishment of the Jin Dynasty, Sima Shi was posthumously honored as Emperor Jing.
After Sima Shi's death, his younger brother Sima Zhao was no less cunning. Disregarding the Wei court's command to garrison at Xuchang, he suddenly led a large army back to Luoyang, gaining the titles of Grand General and Chief of Staff, fully controlling the military and political powers of the Wei court. During his rule, Wei Emperor Cao Mao "rebelled" and was killed, and another member of the Wei royal family, Gaoxiangong, was installed as a puppet emperor. "Sima Zhao's ambitions were clear to all!"
Sima Zhao, enfeoffed as King of Jin in the Wei court, repeatedly wanted to establish his second son, Sima Yi, as heir. First, Sima Zhao and his older brother Sima Shi had a deep bond, often telling his subordinates, "The realm belongs to Jingwang (Emperor Jing, Sima Shi's posthumous title before the establishment of the Jin Dynasty)!" Therefore, adopting Sima You as heir was also Sima Zhao's way of honoring his deceased brother (Sima Shi was Sima Yi's legitimate eldest son, and Sima You, adopted by Sima Shi, should logically inherit the main line). Second, Sima You was described as "clear-minded, peaceful, fair, close to virtuous scholars, fond of giving, loving classics, capable of composing essays, and skilled in letter-writing," with a good reputation, "his talent and prestige surpassing Emperor Wu (Sima Yan)," making him a fine candidate. To the point that every time Sima Zhao saw this second son adopted by his brother, he would pat his own seat affectionately and call him by his nickname, "Taofu, this is your seat!"
Due to the persistent advice of Sima Zhao's close associates He Zeng and Jia Chong, who claimed, "The Middle Guard General (Sima Yan's position in the Wei court) is wise and martial, possessing extraordinary talent. His hair reaches the ground, his hands extend beyond his knees, this is not the appearance of a subject!" With the bloodline of a schemer, perhaps the statement that Sima Yan "is not the appearance of a subject" touched Sima Zhao's heart, who always desired to overthrow the Wei dynasty. Moreover, Sima Yan was his legitimate eldest son, and in the end, he did not decide to place his second son, Sima You, as heir.
Emperor Wu Sima Yan deeply suspected that his dignified and handsome younger brother, Prince Qi Sima You, was his strongest competitor. Knowing one's son is like knowing one's father, and observing one's son is like observing one's mother. On his deathbed, Sima Zhao still struggled to tell Sima Yan and Sima You the story of the conflict between Emperor Huan of Han and Liu An, and between Emperor Wen of Wei and Cao Zhi, advising them to support each other, "On his deathbed, he held Sima You's hand and handed it to Emperor Sima Yan." The Empress Dowager Wang, on her deathbed, also tearfully told Sima Yan, "Taofu (Sima You's nickname) is quick-tempered, and you, as an older brother, are not kind. If I die, I fear you two will not tolerate each other. I hope you can be friendly to your younger brother and refrain from private grievances."
Prince Qi Sima You was indeed not a hypocritical or ambitious false prince. After Emperor Wu ascended the throne, Prince Qi Sima You "commanded the military and pacified internal and external affairs," achieving great accomplishments. "Whenever there were floods or droughts, the common people benefited from relief, reducing taxes by twenty percent, and the whole country depended on him," showing great care for the officials and commoners within the Jin Dynasty and his own fiefdom. "He humbled himself and treated others with trust," continuously advising Emperor Wu to focus on agriculture, prioritize fundamentals, and eliminate extravagance and pursue frugality. Inside and outside the court, everyone was pleased to have such a steady, kind, and harmonious prince.
"As Emperor Wu grew old, all his sons were weak, and the crown prince was not virtuous. Both inside and outside the court, everyone looked to Prince Qi." Fearing that after Emperor Wu's death, Prince Qi would succeed and threaten their positions, the sycophants around Emperor Wu, including the Chief Secretary Xun Xu and the Attendant Feng Dan, slandered Emperor Wu: "After Your Majesty's passing, the crown prince will not be able to ascend the throne." Startled, Emperor Wu asked, "Why?" Xun Xu replied, "Officials inside and outside the court all favor Prince Qi. How could the crown prince ascend?" Feng Dan added, "Sending feudal lords to their fiefs is a national law and should start with relatives. No one is closer than Prince Qi, so he should lead the order and leave the capital for his fief."
With preconceived notions, Emperor Wu readily agreed. He issued an edict, feigning the addition of Jinan County to Prince Qi's fief and enfeoffing Sima You's son, Sima Jian, as King of Beihai, granting him six ceremonial dancers and yellow silk carriages, ordering Prince Qi Sima You to take up his post in his fief.
Upon receiving the edict, ministers like Wang Hun, Wang Jun, Yang Xiu, and Wang Ji fervently advised against it, believing that Prince Qi was a close relative and should remain in the capital to assist in governance. They also cited the last wishes of Sima Zhao and the Empress Dowager, using historical precedents to persuade Emperor Wu to rescind the order. Ignoring their pleas, Emperor Wu said, "Brothers are the closest relatives. Sending Prince Qi away is our family matter," dismissing Wang Hun, Wang Ji, and others to posts outside the capital.
Filled with worry, anger, and hatred, and aware of the schemes of Xun Xu and Feng Dan against him, Prince Qi Sima You petitioned to stay and guard the tomb of his deceased birth mother, Empress Dowager Wang, but "the emperor did not allow it." Seeing the increasingly urgent orders to leave for his fief, Sima You became more anxious and his illness worsened.
To determine whether his younger brother was pretending to be ill to delay leaving, Emperor Wu continuously sent palace physicians to examine Prince Qi. "All the doctors followed the emperor's will and reported that he was not ill." The court physicians, adept at reading the emperor's mind, consistently reported that Prince Qi was perfectly healthy.
In reality, with the emperor's urgent orders, Prince Qi Sima You's condition worsened daily, but the increasingly strict orders left no room for delay.
Prince Qi Sima You had a stubborn nature, akin to "standing firm in the wind until frozen to death." Even though he was almost unable to walk, he still struggled to put on formal attire, combed his hair neatly, and entered the palace to bid farewell to Emperor Wu. "Though sick, he maintained his composure, acting as usual. The emperor became even more suspicious that he was not ill." The two brothers parted ways with their own thoughts, shaking hands goodbye. A few days after leaving, the exhausted Prince Qi finally collapsed halfway and died from spitting blood, at the young age of thirty-six.
Upon learning of his younger brother's death, Emperor Wu realized that Sima You was not pretending to be ill but truly dead. Overcome with grief, he wept bitterly. Attendant Feng Dan skillfully consoled him, saying, "Prince Qi was overly ambitious, and the whole world leaned towards him. Now that he has died of illness, it is a blessing for the state. Why should Your Majesty grieve so much?" "The emperor wiped away his tears and stopped crying."
At the funeral, Sima You's son, Sima Long, prostrated himself and wailed, accusing the court physicians of falsely claiming his father was not ill, delaying treatment. Feeling remorseful, Emperor Wu also took the opportunity to issue an edict executing several court physicians who had examined Prince Qi, thereby covering up his own mistake.
Crying aside, feeling remorse aside, Emperor Wu likely sighed inwardly: this valiant and intelligent younger brother would no longer threaten his son's imperial position.
Objectively speaking, with such a foolish crown prince, Emperor Wu would have been better off leaving the throne to his same-father-and-mother younger brother, Sima You. Judging by reason, the naturally filial, gentle, and humble Sima You, if he truly inherited the throne, would not have harmed his foolish nephew. Moreover, a country relies on a mature ruler, and Sima You possessed rich military and governance experience. The Jin Dynasty's reign might have taken on a different, more prosperous appearance. But history allows no "ifs" or assumptions. Existence is fact. The direct-line inheritance of the father-son imperial system cannot be easily shaken, and each historical figure has their unique, predetermined fate!