A major public confrontation between Imperial Academy students and eunuchs in 166 evolves into a major incident.

The governor of the capital province (modern western Henan and central Shaanxi), Li Ying, had arrested and executed a fortuneteller named Zhang Cheng, who had had his son kill a man, having predicted that a general pardon was coming.

Li is arrested, and some two hundred Academy students sign a petition requesting his release—which further angers Emperor Huan, who has the students arrested.

Only after about a year, and Dou Wu's intercession, are Li and the students released, but all of them have their citizenship rights stripped.

This incident is later known as the first Disaster of Partisan Prohibition.

As recorded in the Hou Hanshu, a possible contact between Rome and Han China occurs in 166 when a Roman traveler visits the court of Emperor Huan, claiming to be an ambassador representing a certain Andun, who can be identified either with Marcus Aurelius or his predecessor Antoninus Pius.

Rafe de Crespigny asserts that this was most likely a group of Roman merchants.

(de Crespigny, Rafe.

[2007].

A Biographical Dictionary of Later Han to the Three Kingdoms (23–220 AD).

Leiden: Koninklijke Brill.)

Other travelers to Eastern-Han China include Buddhist monks who translate works into Chinese, such as An Shigao of Parthia, and Lokaksema from Kushan-era Gandhara, India.