In the ninth year of Wude, a mysterious book circulated in Chang'an City, which was written as "The Complete Collection of Li Erlang's Black Materials". The content was shocking:
- Page 2: Li Shimin was hanged upside down by Princess Pingyang at the gate of Jinyang City at the age of 8 for stealing soufflés as tribute to the Turks;
- Page 15: On the eve of the Weishui Alliance, Tian Khan hid behind a screen to practice Turkic dance and trampled on three pairs of silk shoes of Empress Changsun;
- Page 38: There is a hidden mystery in the Lingyan Pavilion portrait - Yuchi Gong's armor has biscuit crumbs stuffed in the gaps, and Fang Xuanling has "The Art of War Against Disciples" (the posthumous work of Princess Pingyang) under his feet.
**"My Zhenguan prosperous age was created by these enemies!"**
——When Li Shimin looked at the portrait of Lingyan Pavilion and sighed, he would not have known that there was a volume of "Guide to Fighting the Emperor" buried in Wei Zheng's tomb, and the title page was written by Princess Pingyang:
**"If future emperors disobey, beat them in this way."**
