In fact, it doesn't matter whether Song really became lamp oil now. During the Song Dynasty, the imperial court was weak, officials were corrupt, and traitors emerged in large numbers. They were afraid of death. These are all reasons. A historian should study the root of things, not be wise after the event. The so-called taking history as a mirror is to prevent this from happening, whether it is true or not.
At that time, Nomads from Yue Fei and Yue Jiajun were frightened and fled. But in the imperial court, to be no.1's Yue Fei was not promoted or praised, but was impeached by the prime minister at that time on trumped-up charges. Song was impeached by his prime minister at first sight. Can you not panic? After all, it was the prime minister, not Yue Fei, who was with Song at that time, just as the emperor and eunuch were closely related. So, one day at 12, he went to find a token and told Yue Fei to go back to North Korea to die. Yue Fei saw that if my minister died, I would die, too, so he returned to Beijing and died.
So, nomads from like nobody's business, has been killed in the capital, so, just culpable of punishment.
Therefore, studying history is not a textual research on these broken things, but why they are boiled into lamp oil. Studying history is to face history squarely, not to make money with it.