Du Changqing, an ordinary gatekeeper at the Xuanwu Gate. He was a low-level military officer who only wanted to guard the gate and live a safe life. From "escape from history" to "face history", from "guarding a city gate" to "guarding a truth", the change of Xuanwu Gate was not simple. "Good guys vs. Bad guys", Li Jiancheng may not be a mediocre person, and Li Shimin may not be a perfect king. History is written by the victors, but it does not mean that the losers are useless. Use the eyes of an ordinary gatekeeper to re-examine the most famous coup in Chinese history.
