The textbooks we have studied have a comprehensive evaluation and record of our history, including all the dynasties in ancient times, but two dynasties did not appear in the textbooks. These two dynasties were famous short-lived dynasties in history.
First, Wang Mang's new regime.
Many people have heard the story of Wang Mang usurping the Han Dynasty. Wang Mang stepped onto the throne of the emperor step by step by his own ability and established a new dynasty. But Wang Mang's new dynasty is called the dynasty with the shortest existence time in history. It took fifteen years from the establishment of the new dynasty to its end. Although he is also a unified dynasty, there are many controversies about the new dynasty. Because of Wang Mang, the Han Dynasty was divided into five parts.
Second, Wu Zetian's Wu Zhou regime.
Wu Zetian is the only orthodox queen in Chinese history. She spent a lot of money to reach the top. As we all know, Wu Zetian is a very scheming woman. Even her own daughter could be killed to get ahead. Although Wu Zetian had a good command of the country, she was not recognized by her subjects in the end. Later, Wu Zetian was still in Li Tang, and the world became the Tang Dynasty again. In this way, Wu Zetian's regime of Wu Zhou became an episode of the Tang Dynasty.
Third, because these two dynasties are closely related to their former and later dynasties, they are not described too much.
Wang Mang's new regime was mixed in the middle of Han Dynasty, and Wu Zetian's regime of Wu Zhou was mixed in the middle of Tang Dynasty. Although it did exist, there is no clear conclusion about whether it belongs to the Han Dynasty and the Tang Dynasty, so even the textbooks are not mentioned.