Eastern Mediterranean 62 AD: Battle of Rhandeia

At first it appeared as though the Parthians might ignore the Roman intervention in Armenia (58–59 AD), but in 61 AD the new Armenian king attacked the Parthian client state of Adiabene. In retaliation, Shah Vologases invaded Armenia, restoring his brother Tiridates to power. The Romans responded by sending in two armies, only to suffer a humiliating defeat when one of their commanders was surrounded and forced to capitulate at Rhandeia. At the peace treaty which followed, Rome agreed to acknowledge Tiridates as king of Armenia while Tiridates agreed to swear loyalty to Rome.

Main Events

61 AD Armenian–Adiabeni War

In 61 AD the Roman-backed Tigranes VI of Armenia invaded neighboring Adiabene, a client state of the Parthian Empire. King Monobazus II of Adiabene called on Shah Vologases for help. The Shah—who had not retaliated when the Romans had deposed his brother Tiridates from the Armenian throne in 58–59—felt compelled to respond swiftly, abandoning his ongoing war in Hyrcania to deal with the situation.in wikipedia

61–62 AD Second Restoration of Tiridates I

In 61 AD, in retaliation against Tigranes VI of Armenia’s invasion of Adiabene, Shah Vologases I of Parthia proclaimed his brother Tiridates king of Armenia for the third time. The Parthians then invaded Armenia, but were repeatedly repulsed attempting to capture the Roman-garrisoned southern capital of Tigranocerta. After Roman emperor Nero rejected Vologases’ peace offers, the Parthians launched a second invasion in 62 AD, this time successfully forcing Tigranes from his throne.in wikipedia

62 AD Battle of Rhandeia

In response to the Parthian invasion of Armenia, two Roman armies under the leadership of the veteran general Gnaeus Domitius Corbulo and the consul Lucius Caesennius Paetus were dispatched to the east. While Corbulo secured Syria, Paetus launched a limited invasion of Armenia but was caught by surprise by the Parthians as he withdrew to winter quarters in Sophene. Surrounded at Rhandeia and with collapsing morale, Paetus surrendered before Corbulo could come to his aid. The defeat was a shock to the Romans, who were so confident of victory that the Senate had even decreed trophies and arches be erected on Capitoline Hill in preparation for the triumph.in wikipedia