[2] Cui Yuan lost his father when he was young, and he was said to be poor but having great ambitions, studying military strategies fervently.
After the military governor An Lushan rebelled in 755, Yang considered the possibility that the emperor might have to flee to Jiannan, and secretly instructed Cui to begin preparing for such a plan.
In 756, as An's forces approached Chang'an, the plan was carried out, as Emperor Xuanzong began the flight to Jiannan—although, on the way, Yang was killed by angry imperial guard soldiers.
In order to show favor to Cui, however, Emperor Xuanzong erected a monument at Shu Commandery to commemorate his accomplishments.
Afterwards, he submitted a petition asking for punishment, and Emperor Suzong stripped him of his fief and his honorary title as Kaifu Yitong Sansi (開府儀同三司).