The main reason is that there were problems in the inheritance of the imperial throne, Liu Bang passed the throne to the Han Hui Emperor Liu Ying after his death, Liu Ying died in 187 BC, and Liu Heng took the throne in 179 BC, a difference of eight years, so it is said that the Han Dynasty established by Liu Bang perished after Liu Heng ascended the throne.
Only by combing through in detail what happened in the eight years from the death of Emperor Hui of Han to the ascension of Emperor Liu Heng of Han to the ascension to the throne can we fully understand this matter.
Liu Bang had a total of 8 sons, Liu Ying was born to Liu Bang and Lü Hou, although Liu Bang had plans to pass the throne to his son Liu Ruyi, who was born to Lady Qi, but in the end he did not succeed, after Liu Ying took the throne, Lü Hou took power and adopted a liquidation policy against his former enemies, and in the case of being overly suppressed, the young Liu Ying died of depression.
After Liu Ying's death, Lü Yan established Liu Ying's three-year-old son Liu Gong to succeed to the throne, because Liu Ying's empress Zhang Yan had no heirs at that time, Lü Yan passed Liu Gong over to Zhang Yan, and killed Liu Gong's biological mother, as Liu Gong grew up, he hated Lü Gong and others very much, and said that he would avenge his mother when he grew up, who knew that this word reached Lü Yan's ears, so Lü Yan began to depose Liu Gong, and finally put him to death.
After Liu Gong was deposed, Lü Yan established Liu Ying's other son Liu Hong as emperor, and because of Liu Gong's previous experience, the young Liu Hong worked diligently and did not dare to offend Lü Yan at all, resulting in Liu Hong being a puppet during his reign, not even having a year name.
It was not easy to survive until Lü Yan's death, and what Liu Hong did not expect was that the ministers who opposed the Lü clan in the DPRK jointly launched a coup d'état to eliminate the political power of the Lü family.
In the face of Liu Hong's problem, the anti-Lü chancellor clique also had a contradiction and did not know how to deal with it, because although Liu Hong was the emperor, he was also regarded as the emperor supported by the Lü clan, and it was not easy to abolish it, after all, from a legal point of view, Liu Hong, as Liu Ying's son, was the emperor of liu's Jiangshan of the Eight Classics, and in order to overthrow Liu Hong, these conspiratorial ministers simply made up a reason of their own, saying that Liu Hong was not Liu Ying's own son, but a descendant of the Lü clan, and it was Lü Yan who killed Liu Hong in order to control the power and make Li Daitao stiff In addition, even several of his brothers were killed, which is equivalent to cutting off liu Ying's lineage.
This is basically equivalent to the regime established by Liu Bang to carry out a great purge, of course, those old ministers still remember Liu Bang's good, and do not have the strength to completely overthrow liu shi, and finally after a series of considerations, it is decided to choose Liu Bang's other sons to inherit the throne.
Liu Bang had 8 sons, except for Liu Ying, the han hui emperor, the eldest son Liu Fei had died in the sixth year of the Han Hui emperor, most of the other sons were liquidated during the reign of Lü Hou, the fifth Liu Hui was forced to die by Lü Yan, the old sixth Liu You was starved to death by Lü Yan, the eighth Liu Jian also died before Lü Jie, after Liu Jian's death, Lü Yan also sent someone to remove his son.
That is to say, after Lü Yan's death, only the fourth liu heng and the seventh liu chang were left among Liu Bang's sons, but the seventh old Liu Chang was raised by Lü Yan and was the only prince who was not suppressed during Lü Yan's reign, so naturally it was not in the scope of consideration.
After repeated deliberations among the ministers, it was finally decided to appoint Liu Heng as emperor, and the emperor was actually chosen by the ministers, and it is no wonder that some people say that the Han Dynasty established by Liu Bang has perished.