The most typical one is Emperor Gaozu Liu Bang. In order to gain more support, Liu Bang, the Emperor Gaozu of Han Dynasty, also struggled. The mystery of his life story is called "Fighting Dragons in the Wild", which comes from Historical Records and Biography of Emperor Gaozu. It is said that Liu Bang's mother, Liu Wei, fell asleep in osawa one day, and then dreamed there that she met a fairy and was dreaming desperately. When Liu Dagong went to look for it, he found that the sky had changed at that moment, like lightning and thunder. Then I saw a dragon lying on Liu Wei. Not long after he came back, Liu Wei became pregnant and gave birth to Emperor Gaozu Liu Bang.
Followed by Tuoba GUI, the founding emperor of the Northern Wei Dynasty. According to legend, when he was born, his mother dreamed that a red sun would rise in the east. When she woke up, she found a room full of red light, and then she gave birth to Tuoba GUI under the red light. Sure enough, Tuoba GUI was outstanding and finally became the first emperor of the Northern Wei Dynasty.
Finally, the date of birth of Zhu Yuanzhang, the founding emperor of the Ming Dynasty, is also different from ordinary people. It is said that when Zhu Yuanzhang was born, there was lightning, strong wind and hail. As a result, at the moment of Zhu Yuanzhang's birth, these visions disappeared immediately, followed by a brilliant sun.
Personally, I think that the reason why ancient emperors invented such absurd life stories should be that they took it for granted that they became a generation of emperors and let the people know that it was God's will to become emperors.