Because the King of Tang is Tang Suzong Hengli, the son of Emperor Xuanzong of Tang Dynasty, and if Emperor Xuanzong of Tang Dynasty wants to return to Beijing, Tang Suzong can't stand the existence of Emperor Xuanzong of Tang Dynasty, and he will definitely feel that Emperor Xuanzong of Tang Dynasty is a threat to himself. In order to make his throne more stable, Tang Suzong will definitely choose to kill his father. So at this time, Tang Xuanzong insisted on not returning to Beijing.

First of all, before Tang Suzong Hengli succeeded to the throne, he was afraid of his father Li Longji. Because, Tang Xuanzong was very unfriendly and even cruel to his sons, such as the famous Tang Xuanzong in history? Kill three kings in one day? Do you want to be soft on killing your own son, so that when Li Mao saw that Tang Xuanzong had ideas about his wife, Li Mao quickly gave his wife to Tang Xuanzong.

Therefore, the ruthless image of Tang Xuanzong had a great influence on his sons. Although Hengli is a prince, he is not treated well. Even before that, because of Li's existence, Emperor Xuanzong of the Tang Dynasty tried to abolish the prince several times. After the whole of Li Longji, Hengli hated Li Longji very much, and of course there was more hatred.

After the Anshi Rebellion, Li Longji lost the popular support, so he held the flag of the world, put down the rebellion, and then proclaimed himself without authorization. On the one hand, we need a new leader. On the other hand, Hengli finds this a very good opportunity. When the world is stable, because Hengli is not orthodox after all, Xuanzong is still outside.

So in any case, Hengli wanted Tang Xuanzong to return to Beijing, but there was nothing related to the throne in the letter to Tang Xuanzong, saying that it was brought back because of family ties. Therefore, Tang Xuanzong saw clearly that he would be killed by Hengli as soon as he returned to Beijing, so he decided not to go back, and Hengli was also happy to see such a situation.