The so-called concubine line is the first son born to the empress and the emperor, that is, the eldest son. For example, when Zhu Yuanzhang was the ancestor of the Ming Dynasty, the crown prince Zhu Biao was the eldest son, so Zhu Biao's line was the long line.
So is there a dynasty in Chinese history whose imperial throne is entirely in the same line as the Great Patriarch? The answer is no.
Take the 12 great unified dynasties of Qin, Western Han, Xin, Eastern Han, Western Jin, Sui, Tang, Zhou, Northern Song, Yuan, Ming, and Qing as examples.
The founding emperor of the Qin Dynasty was the first emperor Yingzheng, and his successor was Qin II Yinghu Hai. The First Emperor Yin Zheng did not have an empress, so the Qin Dynasty did not have the eldest son, and the second Hu Hai was only the eighteenth son of the First Emperor, not even the eldest son, so how could it be the first son?
The founding emperor of the Western Han Dynasty was Liu Bang, the ancestor of Han Gao, and his successor was Liu Ying, the Emperor Hui of Han. Liu Ying was the first son of Empress Lü Yan and Liu Bang, the eldest son of Concubine. After Liu Ying's death, it is reasonable to say that the throne should pass to him and the eldest son born to Empress Zhang Yan, but Liu Ying and Zhang Yan had no heirs, and Zhang Yan was still a virgin until her death.
Liu Ying was succeeded to the throne by Liu Gong, who was Liu Ying's eldest son, not concubine. Therefore, after Liu Ying, the throne of the Han Dynasty was no longer in the hands of the Concubine Chang.
The new dynasty has only one emperor, that is, Wang Mang, so the new dynasty does not even have a inheritance, how can there be a saying that it has been passed on to the great emperor!
The founding emperor of the Eastern Han Dynasty was Liu Xiu, the Emperor of Han Guangwu, and his successor was Liu Zhuang, the Emperor of Hanming. Liu Zhuang was the first son born to Empress Yin Lihua and Liu Xiu, the eldest son. After Liu Zhuang's death, his successor was Liu Zhuang,the Emperor of Han Zhang, who was not born to empress dowager, and his mother was only a nobleman, so after Liu Zhuang, the throne of the Eastern Han Dynasty was no longer in the hands of the concubines.
The founding emperor of the Western Jin Dynasty was Sima Yan, the Emperor of Jinwu, and his successor was Sima Zheng, the Emperor hui of Jin. Although Sima Zheng was born to Empress Yang Yan and Sima Yan, he was not the first son, but the second son, that is, the second son, and the eldest son was Sima Yan. Therefore, after Sima Yan, the throne of the Western Jin Dynasty was no longer in the hands of the Concubine Chang clan.
The founding emperor of the Sui Dynasty was Yang Jian, the Emperor wen of Sui, and his successor was Yang Guang, the Emperor of Sui. Although Yang Guang was born to Empress Dowager Jia Luo and Yang Jian, he was not the eldest son of Concubine (嫡長子 was Yang Yong), but the second son of Concubine. Therefore, after Yang Jian, the throne of the Sui Dynasty was no longer in the hands of the Concubine Chang clan.
The founding emperor of the Tang Dynasty was Li Yuan, the Emperor Gaozu of Tang, and his successor was Li Shimin of Tang Taizong. Although Li Shimin was born to Empress Dou and Li Yuan, he was not the eldest son of Concubine, the eldest son of Concubine was Li Jiancheng, and Li Shimin was only the second son of Concubine. Therefore, after Li Yuan, the Tang Dynasty throne was no longer in the hands of the Concubine Chang clan.
The Zhou Dynasty only had one emperor, that is, the first and only female emperor in China, Wu Zetian, and like the new dynasty, he also died in the first dynasty, and there was no inheritance to speak of.
The founding emperor of the Northern Song Dynasty was Zhao Kuangyin, the taizu of the Song Dynasty, and his successor was Zhao Guangyi, the Emperor Taizong of Song. Zhao Guangyi was Zhao Kuangyin's younger brother, not even a son, so how could there be a distinction between concubines and concubines!
The founding emperor of the Yuan Dynasty was Kublai Khan, the ancestor of the Yuan Dynasty, and his successor was Emperor Yuanchengzong Tiemu'er. Timur was Kublai Khan's grandson, and he was the third son of Kublai Khan's eldest son, Zhenjin, not the eldest son, so after Kublai Khan, the throne of the Yuan Dynasty was no longer in the hands of the Concubine.
The founding emperor of the Ming Dynasty was Zhu Yuanzhang, the Ming Emperor, and his successor was Zhu Yunjiao, the Ming Hui Emperor. Zhu Yunjiao was the grandson of Zhu Yuanzhang, his father was Zhu Biao, the eldest son of Zhu Yuanzhang, and although his father was the eldest son of Zhu Yuanzhang, Zhu Yunjiao was only the eldest son of Zhu Yuanzhang. Therefore, after Zhu Yuanzhang, the imperial throne of the Ming Dynasty was no longer in hand.
The founding emperor of the Qing Dynasty was Emperor Taiji of the Qing Dynasty, and his successor was The Qing Dynasty Zu Fulin. Fu Lin was not the eldest son of Concubine, but only the ninth son of Emperor Taiji. Therefore, after the Emperor Taiji, the throne of the Qing Dynasty was no longer in the hands of the Concubine.
Think about it, even the Great Unification Dynasty can't completely control the throne in the hands of the Concubine Lineage, let alone divide the dynasty!