Marcus Aurelius: The Double Emergency

The Parthian War and the Plague161–169

The new reign's opening lesson was that a perimeter has two ends. Antoninus was five months dead when Vologases IV moved: the Roman client on the Armenian throne expelled, a Cappadocian legion — the Ninth Hispana's eastern successor formation under the legate Severianus, urged on by an oracle — annihilated at Elegeia with its commander's suicide, the governor of Syria beaten in the field, and the Euphrates provinces open. The war that followed (162–166) was conducted for the co-emperor Lucius Verus, who held the court at Antioch, by the professionals whose careers it made: Statius Priscus retaking Armenia and storming Artaxata in 163; Avidius Cassius — the Syrian legate whose name the volume will meet again — driving down the Euphrates in 164–165, breaking the Parthians at Dura-Europos and Sura, taking Seleucia and burning Ctesiphon's palace; Martius Verus securing the north. The settlement restored the Neronian architecture with Roman interest: an Arsacid client in Armenia, northern Mesopotamia's approaches garrisoned, Dura and Nisibis held permanently — the frontier pushed to a line the Severans would inherit. And out of Seleucia in 165–166 the army carried home the reign's true enemy. The Antonine plague — smallpox on the modern reading, arriving with the returning legions and running the empire's roads for a generation, recurring to 189 when Dio records two thousand dying daily at Rome — is the volume's largest and least narratable event: mortality estimates range from a tenth to a third of the population, the papyri show Egyptian villages losing a third of their taxable men, the frontier armies were gapped, the mints thinned, and Galen, who fled it and described it, becomes for this compendium's purposes a military source, because an army that cannot be recruited cannot hold a line. The triumph of 166 was celebrated over Parthia with the disease already in the city.

The Marcomannic Wars166/7–180

Into that weakened perimeter, at the moment of its weakness, came the northern movement — and the Editor states its character as the modern evidence permits: not a raid but a pressure, whole peoples in motion across the middle Danube's far bank, the Marcomanni and Quadi of Book VI's client-system leading a coalition that included Sarmatian Iazyges, Vandals, Naristi, Cotini, and, in the reign's most alarming intelligence, the Lombards and Obii appearing on the river with six thousand men in 166/7. The first shock (167–170) broke through: the frontier forced, Dacia's approaches raided, the praetorian prefect Furius Victorinus dead with his army in an unrecorded disaster, and in 170 the invasion that reached the Adriatic — Opitergium destroyed, Aquileia besieged, barbarians in Italy for the first time since Marius, while the Costoboci simultaneously drove through the Balkans to sack the sanctuary at Eleusis. The emperor's response was total mobilization by improvisation: two new legions raised (II and III Italica), gladiators, bandits, Danubian irrigation-workers, and German auxiliaries taken into service; the imperial ornaments and the palace furnishings auctioned in the Forum to fund it; and the establishment of a new command architecture — the praetentura Italiae et Alpium, Italy garrisoned as a theater for the first time in three centuries. From 171 to 175 Marcus fought the northern war in person from Carnuntum and Sirmium, and the counteroffensive's episodes survive chiefly as images on the Aurelian column and reliefs: the Quadi trapped and destroyed on the frozen Danube — the Roman infantry, Dio says, bracing shields on the ice against the enemy's slipping horses; the "rain miracle," a thunderstorm breaking an encircled legion's thirst that pagan and Christian traditions promptly claimed for rival divinities, carved on the column as a rain-god with water streaming from his arms; the Sarmatian settlement of 175 that returned a hundred thousand Roman captives and took eight thousand Iazyges horsemen into Roman service, five and a half thousand of them posted to Britain. The war was interrupted by the revolt of Avidius Cassius in Syria (175, three months, ended by a centurion's initiative) and resumed in 177 when the Danube broke again; Marcus went north for the last time with his son Commodus, and the campaigns of 178–180 drove into the Quadi and Marcomanni homelands with what the sources represent as a plan for annexation — two provinces, Marcomannia and Sarmatia, on the Trajanic model. The emperor died in camp at Vindobona or Sirmium on 17 March 180, of plague or exhaustion, aged fifty-eight, having spent the last decade of the empire's most philosophical reign in a tent — and the Meditations, written in those camps, enter this compendium as its strangest primary source: a commander-in-chief's private notebook, containing no campaign, no enemy, and no strategy, and testifying more precisely than any narrative to what the war cost the man conducting it. His son made peace within months on terms the tradition calls a betrayal and the modern literature largely calls arithmetic — subsidies and client-status rather than provinces — and the Editor's verdict follows the strategic logic: the annexation was unaffordable in a plague-thinned empire, and the frontier Commodus bought held for fifty years.