Kill your daughter in order to ascend to the throne
As early as the Tang Dynasty, the killing of Wu Zetian's son had already spread like wildfire.

In 675, Wu Zetian's son died suddenly, and Sima Guang wrote in the Zizhi Tongjian:
"Hehai, the crown prince is in the Hebi Palace." At that time, people thought that the Queen of Heaven was also a dove. ”
Note that the first half of this sentence says that the prince died in the Hebi Palace, but the second half does not fully speak, using words such as "when people think".
That is to say, in Sima Guang's heart, he was not sure whether Wu Zetian's killing of his son was true.
This matter is still suspicious today, and people have different views on it, so in real history, did Wu Zetian really kill his son?
In 1995, Shaanxi unearthed an epitaph, and the contents of this epitaph revealed Wu Zetian's crimes and gave a reasonable explanation for Wu Zetian's killing of his son.
To say why Wu Zetian's killing of his son can be rumored in the dynasty is because Wu Zetian has long had a "previous crime". This incident is no longer a secret, and it is recorded in the New Book of Tang:
Wu Zhaoyi gave birth to a daughter, her eldest daughter, Princess Anding.
The world knows that the mother is gui, at that time, Wu Meiniang was just a Zhaoyi, according to the thinking of normal people, she gave birth to a dragon vein, which is equivalent to having a lean body.
Although this child was a princess, the good villain was her eldest daughter, but Wu Zhaoyi actually used the life of his own daughter as a chip in order to overthrow Empress Wang.
After Princess Anding was born, Empress Wang went to visit Wu Zhaoyi according to the palace system, and after the Empress Wang came, Wu Zhaoyi found an excuse and slipped away.
After Empress Wang came to visit, she routinely rewarded some things, and left when her duties were completed, at this time, Empress Wang probably did not dream of understanding what kind of mother could kill her own child for the sake of her rights.
After Empress Wang left, Wu Zhaoyi immediately quietly returned, covered Princess Anding to death with a futon, and after handling the scene, she quietly left again, pretending that she had never returned.
After Emperor Li Zhi came, he found that Princess Anding had died violently, at which time Wu Zhaoyi told Li Zhi bitterly that only Empress Wang had just come.
In fact, to tell the truth, a little analysis of this matter will find loopholes, not to mention that Wu Zhaoyi was only a daughter, even if she gave birth to a son, it would have no impact on the status of Empress Wang.
Even if you take ten thousand steps back, no matter how stupid the Empress Wang is, she will not blatantly kill the Imperial Daughter, right? The key point should always be quietly harmed.
Of course, perhaps Li Zhi was a "fan of the authorities", he repeatedly listened to Wu Meiniang's seduction, and finally deposed Empress Wang in one breath, and incidentally beat Wu Meiniang's nemesis Xiao Shufei into the cold palace.
To this day, there are still many people who are skeptical about this matter, but throughout the history, there is no substantive evidence that can overturn this matter.
In view of the fact that Wu Zetian already had a previous conviction for killing her son, it was not unusual for her to kill her son later according to her fierceness.
The crown prince Li Hong was actually a rare good prince, although he was born of Wu Zetian, but his disposition was quite benevolent, and it was because of this son's diametrically opposed disposition to himself that wu Zetian was dissatisfied, and finally Li Hong brought himself the disaster of killing.
Why do mothers and children turn against each other?
Li Hong was only 5 years old when he was made crown prince, and there is a saying that in fact, Li Hong, as the eldest son of Wu Zetian, wanted this son to inherit the unification.
Since the beginning of the Wei and Jin dynasties, there has been a saying that Taishang Laojun was reincarnated under the name of Li Hong, plus the Li Tang royal family has always claimed to be a descendant of Laozi, so Wu Zetian named him Li Hong, which is enough to see that her expectations for this eldest son are very high.
In other words, at that time, Wu Zetian did not have the ambition to dominate the world, and her ambition was only to climb up like the women in the harems of the dynasties.
Li Hong has been learning "Left Turn" with his teacher since he was a child, and his heart is very kind, whenever his father is sick, Li Hong is in front of the bed, always in shape.
Many people suffered, and he always proposed to revise the imperial court system, and became famous and loved among the people.
Not only to the people, but also to his own sister is also very kind, when Wu Zetian fought to kill Xiao Shufei, Xiao Shufei's two daughters have been detained by her, both 30 years old and not married.
After Li Hong learned of this incident, he actually asked Wu Zetian to release his two sisters, which did make Li Hong receive a round of praise in the court, but in all fairness, Wu Zetian's heart did not think so.
She had hated Xiao Shufei before, even if she died, her daughter would not think about it, and now her son forced himself to release the daughter of the enemy, was it not a naked punch in her face?
Because of this, Wu Zetian's dissatisfaction with Li Hong gradually increased.
In Li Zhi's later years, his health was even worse, and he was unable to handle state affairs, because Empress Wu Meiniang had great political opinions, so he simply gave up some of his powers and let her handle political affairs.
This was the basis for Wu Zetian's ambitions to blossom.
As the crown prince Li Hong grew up, Wu Zetian's power increased, and Li Zhi, fearing the monopoly of foreign relatives, slowly began to withdraw the power from Wu Zetian's hands and transfer it to Li Hong.
This made the contradiction between Wu Zetian and Li Hong completely explode.
Slowly, Li Hong found that his mother controlled the government and was not willing to give up his power at all, and At this time, Li Hong was already 20 years old, and he did not want to be a puppet emperor.
Based on the fact that the mother and son began to be hostile, in order to compete for power, the two became complete enemies.
In April of the second year of the first century, Wu Zetian poisoned Li Hong with wine.
Of course, Sima Guang's record in the Zizhi Tongjian is actually recorded with a skeptical attitude, after all, Sima Guang was a person during the Northern Song Dynasty.
If Sima Guang did not actually witness the beginning and end of the matter with his own eyes, what Li Bi, a famous minister during the Tang Dynasty, said is worth pondering.
At that time, Li Bi said a passage to Emperor Suzong of Tang, that is, Li Heng, the great-grandson of Wu Zetian:
...... Filial piety to the emperor, for the crown prince overseeing the country, Renming filial piety. After the heavens, the emperor was killed by Filial Piety, and King Xian of Liyong was made crown prince.
The Emperor Xiaojing in Li Bi's mouth was Li Hong, and after Li Hong's death, he was posthumously honored as the Emperor of Xiaojing, to the effect that the crown prince Renming was filial to the emperor, and the Queen of Heaven poisoned Li Hong in order to control the government.
In fact, the amount of information in this passage is very large, if Wu Zetian's killing of his son is false, then Li Bi slandered his great-grandmother in front of Tang Suzong, which is probably not wanting to live.
Therefore, what Li Bi said is most likely true, and posterity also speculates that Wu Zetian killed Li Hong based on Li Bi's words.
Another excavation proves that the history books have not deceived people
In addition to this ironclad evidence of Wu Zetian's killing of his son, a tombstone unearthed in 1995 is also a key piece of evidence of Li Hong's unnatural death.
The owner of this tombstone is called Yan Zhuang, the son of Yan Lide, a major minister of the Tang Dynasty, who served as the prince's family order during his lifetime.
Yan Zhuang also followed Li Hong only 5 months after his death, which was originally nothing, but there is a passage in the epitaph that caught the attention of scholars:
It is not easy to be ignorant of the others, and the blessings are vainly deceived. The accumulation of crusts invaded Russia, entangled in the ant bed and ruined; the floating light was exhausted, and it passed away with the crane version.
This passage is a bit awkward, let's translate it:
God is so ignorant, you can't live a long life, every day you are disturbed by the worries in your heart, because you run in front of the spiritual bed and encounter disasters, your fame is gone, and you disappear with the coffin.
This sentence is enough to show that the cause of Yan Zhuang's death is inseparable from the death of the prince.
You know, the epitaph was originally a person who was born to pay homage to the deceased, usually inscribed with praise, or mourning, this Yan Zhuang epitaph is obviously a bit strange.
The epitaph is not a record of life or mourning, but a vague record of the cause of the owner's death in this regrettable tone, and there is no lack of resentment and injustice in the tone.
In fact, Li Hong's death has always been a mystery, even in the Zizhi Tongjian, Sima Guang did not show wu Zetian's killing of his son with great certainty.
When Tang Gaozong announced to the world after Li Hongxue's death, he said that the prince died of tuberculosis, which is now pneumonia, which was an incurable disease in ancient times.
In the Old Book of Tang, there is no information to prove the authenticity of Wu Zetian's killing of his son, in fact, the information on this matter in the history books has always been incomplete.
It is generally said that a mother kills her son, which is indeed difficult for ordinary people to accept, and for these reasons, whether Wu Zetian really killed her son has always been controversial.
And this unearthed "Yanzhuang Epitaph" just happened to be a strong proof of Wu Zetian's killing of his son, and the history books did not deceive people.
Nowadays, the "Yanzhuang Epitaph" is stored in the museum of Shaanxi Normal University, because of its exquisite calligraphy, coupled with its complete preservation and rich content, it has become the treasure of the Shaanxi Museum.
This tombstone is of great value for the study of the history of the Tang Dynasty.
Although people believe that "tiger poison does not eat children", but for the ancient dynasty, power is above all else, if Wu Zetian is not ruthless, she will never be able to sit on the throne.
In his later years, Li Zhi already had the idea of a Zen throne, plus Li Hong was a prince and was orthodox, that is to say, if Li Hong did not die, the throne would not have Wu Zetian at all.
According to the situation at that time, she and Li Hong were already dead and alive, so if she didn't kill her son, maybe she would die her own.
Of course, we don't need to make too many comments about whether Wu Zetian is cruel or not, and all we can do now is restore history and respect history.
As an empress of a generation, wu Zetian's prosperity and prosperity brought to the Tang Dynasty are undeniable, and when we judge the history of Wu Zetian's ascension to the throne, we should also objectively look at her exploits.