Crassus Invades Parthia

Marcus Licinius Crassus, the richest triumvir and least decorated general among Caesar and Pompey, wanted a war to match their laurels. In 54 BCE, he took Syria as his base, mustered about seven legions with allied horse, and looked across the Euphrates toward Mesopotamia. The target was not a fortress but an empire built for the saddle: the Arsacid Parthians ruled from Seleucia and Ctesiphon, far beyond Rome’s normal reach [1][2].

At Antioch the plan sounded straightforward—push through Osroene, seize cities, fix a boundary. On the ground it meant crossing the Euphrates near Zeugma into flat, thirsty country where horse archers could ride circles around infantry. Crassus dismissed cautions from local allies who urged a riverine approach and sieges, not pursuit. He preferred speed and the glory of a decisive field battle [1][18].

The march east opened with confidence. Trumpets cut the morning air; the creak of wagons followed the legions through Nicephorium toward Carrhae. Crassus expected walls to batter and rams to deploy. The Parthians offered something else entirely: space, dust, and mobility. Cassius Dio’s epitome is blunt: “Crassus goes to war against the Parthians, is defeated and killed.” The stark summary foreshadows the mismatch of method and terrain [2].

Rome’s strength had always been engineering—bridges, camps, and sieges. In open Mesopotamia those strengths mattered less than water skins and arrow resupply by camel. From Ctesiphon, the Parthians sent their great noble Surena with cataphracts and horse archers. He would not defend walls. He would defend emptiness [1][18].

By winter, Crassus had drawn his army into a landscape designed for Parthian archery. The bronze of legionary helmets shone under a hard sun. The only walls were the thin lines of shields. And when the horse archers appeared at range, the battlefield would belong to the bow.