Who ordered the killing of calligrapher Yan Zhenqing?

Yan Zhenqing was killed on orders from Li Xilie.

Yan Zhenqing was a famous calligrapher in Tang Dynasty. He is famous for his regular script and is known as one of the "four masters of regular script". His calligraphy works occupy an important position in the history of calligraphy in China. But he was killed by the rebel Li Xilie on August 23rd, 785 (July 23rd, 785). It is said that the soldiers of the three armed forces shed tears at that time. Six months later, the rebel general Li Xilie was killed by one of his own, and the rebellion was put down.

Generally speaking, Yan Zhenqing was killed by Li Xilie.