The Parthian monarch then invaded Syria and defeated the governor of the province in late 161.
Marcus Aurelius who had become emperor on Antoninus Pius death in 161, wishing to remove his brother Lucius Verus from the seductions of Rome, and give him an opportunity of acquiring military fame.
Lucius Verus and his general Gaius Avidius Cassius were sent with an expeditionary force to subdue the Parthians.
It lasted four years: success was generally on the side of the Romans, and Cassius crossed the Tigris took Ctesiphon and destroyed the royal palace.
The war appears to have been concluded by a treaty, by which the Parthian monarch resigned all claim to the country west of the Tigris.
The real hero of the Parthian was Avidius Cassius, a native Syrian from Cyrrhus, rather than the indolent Emperor Lucius Verus.
Avidius Cassius was a brave soldier, an able general and a strict disciplinarian, whose severity often became cruelty; yet he was loved by the soldiers, and he possessed many great and good qualities.
Roman-Parthian War of Lucius Verus (161–166)
