Campaign History of The Roman Military - Empire - Early To Middle (30 BC – 180 AD) - Struggle With Parthia (114–217)

Struggle With Parthia (114–217)

By the 2nd century AD the territories of Persia were controlled by the Arsacid dynasty and known as the Parthian Empire. Due in large part to their employment of powerful heavy cavalry and mobile horse archers, Parthia was the most formidable enemy of the Roman Empire in the east. As early as 53 BC, the Roman general Crassus had invaded Parthia, but he was killed and his army was defeated at the Battle of Carrhae. In the years following Carrhae, the Romans were divided in civil war and hence unable to campaign against Parthia. Trajan also campaigned against the Parthians from 114-117 and briefly captured their capital Ctesiphon, putting the puppet ruler Parthamaspates on the throne. However, rebellions in Babylonia and the Jewish revolts in Judea made it difficult to maintain the captured province and the territories were abandoned.

A revitalised Parthian Empire renewed its assault in 161, defeating two Roman armies and invading Armenia and Syria. Emperor Lucius Verus and general Gaius Avidius Cassius were sent in 162 to counter the resurgent Parthia. In this war, the Parthian city of Seleucia on the Tigris was destroyed and the palace at the capital Ctesiphon was burned to the ground by Avidius Cassius in 164. The Parthians made peace but were forced to cede western Mesopotamia to the Romans.

In 197, Emperor Septimius Severus waged a brief and successful war against the Parthian Empire in retaliation for the support given to rival for the imperial throne Pescennius Niger. The Parthian capital Ctesiphon was sacked by the Roman army, and the northern half of Mesopotamia was restored to Rome.

Emperor Caracalla, the son of Severus, marched on Parthia in 217 from Edessa to begin a war against them, but he was assassinated while on the march. In 224, the Parthian Empire was crushed not by the Romans but by the rebellious Persian vassal king Ardashir I, who revolted, leading to the establishment of Sassanid Empire of Persia, which replaced Parthia as Rome's major rival in the East.

Throughout the Parthian wars, tribal groups along the Rhine and Danube took advantage of Rome's preoccupation with the eastern frontier (and the plague that the Romans suffered from after bringing it back form the east) and launched a series of raids and incursions into Rome's territories, including the Marcomannic Wars.