Why did the emperor's father and son Song Xiaozong and Zhao Dun die of old age?

Because Zhao Dun is always at odds with his father and his wife doesn't like his father-in-law, she always stirs up trouble. The main reason is that although Song Xiaozong abdicated, he still manages many things, which makes Zhao Dun very unhappy. As the saying goes, two tigers are not allowed in one mountain. Song Xiaozong has been emperor for decades, and the habit of being above ten thousand people still exists. These have become a thorn in Zhao Dun's heart. Naturally, he dislikes his father more and more.

In fact, this Song Xiaozong still likes his youngest son, Zhao Dun. Otherwise, the throne will never fall to his old man. Song Xiaozong also has the right to fight again. He is fearless. He made Mozi Zhao Dun a prince early and gave Zhao Dun hope, but he refused to abdicate. He also threatened that the prince was young, inexperienced and talented, which angered Zhao Dun. Therefore, as soon as Zhao Dun ascended the throne, he obviously showed his dislike for his father.

What made Zhao Dun angry most was that Song Xiaozong suggested that his brother's son should be a prince, not his own son, which made the bad blood between father and son grow bigger and bigger, which was completely irreparable.