The Parthians retreat to Nisibis, but this…

Occupied Armenia is reconstructed on Roman terms.

A new capital, Kaine Polis ("New City" in Greek), replaces Artaxata in 164.

Detachments from Cappadocian legions are attested at Echmiadzin, beneath the southern face of Mount Ararat, four hundred kilometers east of Satala.

It would have meant a march of twenty days or more, through mountainous terrain, from the Roman border.

A new king is installed: a Roman senator of consular rank and Arsacid descent, C. Iulius Sohaemus.

He may not even have been crowned in Armenia; the ceremony may have taken place in Antioch, or even Ephesus.

Sohaemus is hailed on the imperial coinage of 164 under the legend Rex armeniis Datus: Verus sits on a throne with his staff while Sohamenus stands before him, saluting the emperor.

There is little movement in 164; most of the year is spent on preparations for a renewed assault on Parthian territory.

Roman forces, perhaps led by Martius Verus and the V Macedonica, move on Mesopotamia in 165.

Edessa is reoccupied and Mannus reinstalled.

His coinage resumes, too: 'Ma'nu the king' (Syriac: M'NW MLK') or Antonine dynasts on the obverse, and 'King Mannos, friend of the Romans' (Greek: Basileus Mannos Philorōmaios) on the reverse.

Lucius makes another trip to Ephesus in the middle of the Roman-Parthian war, perhaps in autumn 163 or early 164, to be married to Lucilla, the second daughter and third child of his adopted brother, Roman Emperor Marcus Aurelius, and Roman Empress Faustina the Younger.

Lucilla's thirteenth birthday is in March 163; whatever the date of her marriage, she is not yet fifteen.

Marcus had moved up the date: perhaps stories of Panthea had disturbed him.

Lucilla is accompanied by her mother Faustina and M. Vettulenus Civica Barbarus, the half-brother of Lucius' father.

Marcus may have planned to accompany them all the way to Smyrna (the biographer says he told the senate he would); this did not happen.

Marcus only accompanies the group as far as Brundisium, where they board a ship for the east.

Marcus returns to Rome immediately thereafter, and sends out special instructions to his proconsuls not to give the group any official reception.

Lucilla, who becomes Lucilla Augusta, will bear three of Lucius' children in the coming years.

Emperor Huan, perhaps finally fed up with the eunuchs' excess, in 165, demotes Ju, the only one remaining of the original five who had helped him overthrow Liang Ji six years earlier.

Several other corrupt eunuchs are also demoted or deposed, but their powers are soon restored.

For the rest of Huan's reign, there will be a cyclical rising and falling of the eunuchs’ power after conflicts with officials, but each time the eunuchs prevail, becoming more powerful than before.

Emperor Huan, apparently tired of Empress Deng and of her disputes with his favorite, Consort Guo, deposes and imprisons her later in this year.

She dies in anger, and several of her family members are executed.

He wants to bestow the empress title upon another consort, Tian Sheng, but officials oppose this measure because she is of lowly birth, and recommend that he instead elevate Consort Dou Miao, the daughter of Dou Wu, a Confucian scholar and a descendant of Dou Rong, who had contributed much to the establishment of the Eastern Han Dynasty.

Emperor Huan does not favor Consort Dou, but yields to pressure and names her empress.

Avidius Cassius, marching down the Euphrates in 165, defeats the Parthians at Dura-Europus, which city the Romans incorporate into the province of Syria.

A descendent of the Seleucid king Antiochus IV Epiphanes, Cassius is the son of Gaius Avidius Heliodorus, a noted orator who was Prefect of Egypt from 137 to 142 under Hadrian, and wife Junia Cassia Alexandria.

He was born in the town of Cyrrhus in Syria, although he once called Alexandria his 'paternal city'.

It is assumed that Cassius began his career during the reign of Antonius Pius.

Possibly elected as a quaestor in 154, it is assumed that the young vir militaris had been stationed in the final years of Pius’s reign as a legatus in one of the legions stationed along the Danube in Moesia Inferior, watching over the Sarmatians.

Certainly by 161, he was noted as a legatus in the legions.

A strict disciplinarian as the Legatus (General) of Legio III Gallica, he quickly comes to prominence under the emperor Marcus Aurelius during the Parthian War.

Cassius has by year’s end traveled to the south and crossed Mesopotamia at its narrowest point and proceeded to attack the twin Parthian cities on the Tigris River, Seleucia on the right bank, and Ctesiphon, the Parthian capital, on the left.

He captures Ctesiphon and burns the palace of Vologases, and ...

....although Seleucia had opened its gates to the Romans, Lucius destroys it as well, leaving a blot on reputation.

Excuses are sought, or invented: the official version (promulgated, according to the Historia Augusta, by Asinius Quadratus) has it that the Seleuceni broke faith first.

Whatever the case, the sacking marks a particularly destructive chapter in Seleucia's long decline.

During the sacking, Roman troops steal the statue of Apollo Comaeus from its temple; they eventually bring it back to Rome, where it is installed at the temple of the Palatine Apollo.

This blasphemy may have been on Marcus' mind when he called a lectisternium, a great meal offered to the gods, at the beginning of the Marcomannic Wars in 167, to ward off the evils then being visited on the state.

In dire need of supplies, and with his soldiers showing the first signs of having contracted the plague at Seleucia, ...

...Cassius marches back to Syria with the spoils of the campaign.

Sending details of his achievements to Rome, he is rewarded with elevation to the Senate, although officially the campaign is credited to his commander-in-chief, Lucius Verus.

Verus even orders Cassius to write up the events of the campaign so that Verus can write himself into the official history of the campaign.

Lucius is awarded with a triumph on his return from the campaign against Parthia; the parade is unusual because it includes the two emperors, their sons and unmarried daughters as a big family celebration.

Marcus Aurelius' two sons, Commodus, five years old and Annius Verus, three, are elevated to the status of Caesar for the occasion.

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.