For those who are interested in the round houses of Li Shimin and Wu Zetian, the History Encyclopedia editor brings detailed articles for your reference.

As we all know, Empress Wu Zetian was the empress of Emperor Gaozong before she became emperor. However, before Emperor Gaozong, she was still a concubine of Emperor Taizong Li Shimin.
As for why Wu Zetian entered the palace, there is another story about becoming Li Shimin’s concubine. It is said that Wu Zetian was the youngest daughter of the warrior. Wu Zetian and her sister were born to Yang, the stepwife of the warrior Wu. Because Wu followed Emperor Gaozu Li Yuan to conquer the world, Emperor Gaozu Li Yuan rewarded Wu with giving him the daughter of Hongnong Yang as his wife. In that era, social status was highly valued, so the samurai wanted to have a son with Yang, and such a son naturally had the bloodline of a wealthy family.
Unfortunately, both of the children born to Yang were daughters, but despite this, Wu Zetian, the younger daughter, was still deeply loved by the warrior. However, after the death of the samurai, according to tradition, only his son could inherit his title. And his son Wu Yuanlang was not good to Yang’s mother and daughter. When he took over the position of clan leader, his status was not yet stable, so Wu Zetian’s sister married fairly well. When Wu Zetian was about to get married, Wu Yuanlang’s status was already quite stable, so he wanted to retaliate against Yang’s mother and daughter by marrying Wu Zetian to a pig butcher. Wu Zetian was furious and ultimately decided to draft her into the palace.

After Wu Zetian entered the palace, she was naturally favored by Li Shimin due to her youth and beauty. When the two of them were rounding up the house, suddenly a wooden pillar fell down. It is said that at that time, Li Shimin summoned Wu Zetian for a visit, and it was a night of lightning and thunder. As they were about to fall asleep, the thunder hit the beams and pillars of the palace, causing a wooden pillar to fall. In the end, Wu Zetian risked her life to block the beam for Li Shimin, but she was hit by the beam and fainted at the time.
In a certain TV drama, this scene was also played, and even when the crossbeam fell, Wu Zetian was a bit at a loss. At the same time, a book fell down, which wrote a famous ancient prophecy that the female protagonist would rule the world. Li Shimin saw this prophecy and then looked at Wu Zetian beside him. Are these two things related? Upon careful consideration, Li Shimin realized that it was a groundless rumor, so he did not take it seriously.
According to official history, when Wu Zetian entered the palace, Li Shimin was already 39 years old, which was considered relatively old in ancient times. It is even possible to speculate that your citizens have almost never contacted Wu Zetian, as she has been in the palace for 12 years without giving birth to more than half of her children. However, it’s hard to say because Li Shimin’s other concubines never had any children.
After the death of Li Shimin, Empress Wu Zetian, as a concubine of the late emperor, was moved to the Royal Temple of Ganye to become a monk. If there were no unexpected circumstances, she would have spent her entire life here. However, later on, due to the competition for favor in the imperial harem and the unforgettable love between Emperor Gaozong of Tang and Empress Wu Zetian, Empress Wu Zetian finally had a turn of events and returned to the palace to become Emperor Gaozong’s empress. In the end, she became the only empress in ancient China.