Why did Marcus Antonius set out on a huge expedition to Parthia in 37 BCE? Biographers and historians, for example Goldsworthy 2007 and Halfmann 2011, tend to take the answer for granted: all Romans wanted to avenge Marcus Crassus’ defeat and bring back the standards his army lost there, thereby restoring the proper order of world politics. For too long our understanding of Romano-Parthian interaction has been dominated by the assumption, based on the Augustan message, that Rome had to triumph over the Parthians to restore national honour.
I argue that Antonius’ Parthian expedition had less to do with avenging Crassus and everything to do with his rivalry with the younger Caesar. The pact of Brundisium in 40 had surely taught him that he could not dominate his young colleague using the military reserves he already commanded, nor by means of an alliance with the opposition on Sicily. The veterans in Italy, loyal to the dead Caesar’s memory, would not fight against his heir any more than they would fight the “victor of Philippi”. A victory in Parthia was meant to enhance Antonius’ military reputation, even perhaps enabling him to outshine the Dictator Caesar himself.
Reassessments of Romano-Parthian relations (e.g. Noè 1997; Rose 2005; Curran 2007) and contemporary Roman reactions to Crassus’ defeat (Morrell 2017) have yet to have an impact on our understanding of Antonius’ motivation. Noè demonstrated the ease with which Pompeius and those who supported him asked for and gained help from the Parthian dynasty, despite Roman aggression in the 50s. Curran argues that the “war of revenge” was classic “popularis” policy (as distinct from Roman). Morrell argues that, although Pompeius had supported Crassus’ invasion of Parthia in 55, he actively persuaded the senate not to embark on a war of revenge in 53. In other words, the Parthians were not the mortal enemies that later voices made them out to be.
Furthermore, Noè also demonstrates that the incursions of the Parthian prince Pacorus and the “Pompeian” Q. Labienus in 40-39 BCE were more about the continuation of civil war than a “rogue leader” and “adventurer” leading the barbarian hoards against Roman territory. P. Ventidius’ victories had seen off that challenge in 38. Antonius could have stopped there, but chose not to. The immediate military problem had been solved, but not the politics.
I argue, with Welch 2006/7, that Antonius chose to go to Parthia because it presented the only available opportunity to neutralise both generations of the “Caesar” factor. His victory was necessary for political reasons, not to institute a war of expansion. Signs are that he did not intend to follow up with direct annexation of territory. In the period after Philippi and the pact of Brundisium, he had instituted a network of effective ‘friendly kings’, granting them territory when it was deemed necessary. When this policy was criticised in Rome, his riposte was that “greatness” lay in giving away, not accruing territory (Plut. Ant. 36.3). Such moves suggest that the “Pompeian” strategy of installing friendly kings in and around Parthia would have been the most likely outcome of a victory. Defeat did not necessarily mean a change of strategy, but it did mean that Cleopatra, now the only non-Caesarian source of much needed resources, would have a greater say. The “Donations of Alexandria” indicates that their joint children would rule the former empire of Alexander “when it was acquired” (Plut. Ant. 54.4-6; Dio 49.41). In neither case was the territory to come under the direct power of Rome.
Antonius’ aims originally combined a Roman desire to achieve a massive (and powerful) reputation for military success with an extension of Roman influence by soft power to follow. It is a solution that looks more “Pompeian” than “Caesarian”. Even in defeat, Antonius is revealed as a more complicated imperialist than our standard biographies and narrative treatments allow.
New Directions in the Late Republican Roman Empire