Tang Dynasty: My Father Died Unjustly, and the Border Troops Invited Me to Beijing

Eighteen years ago, Prince Li Ying was wrongfully deposed and sentenced to death in Chang'an with an imperial edict. Eighteen years later, Anlushan raised troops and Tongguan was in danger. Emperor Xuanzong of the Tang Dynasty issued another edict, forcing 100,000 soldiers in Helong to leave the border and die. Li Ying's son Li Yan withheld the imperial edict in public and closed Tongguan. "Back then, my father was ordered to die, but he failed to get a word of justice." "Today, I will never let another hundred thousand soldiers die in a random incident!" Chang'an beheaded him and questioned him, but the Helong border army wore armor and held soldiers and sent him to the capital. On this trip, he wanted to put down the rebellion and save the country, and he also wanted to personally question the grandfather who sat on the throne. Eighteen years ago, who conspired to rebel?