Marcomanni, Quadi, and Iazyges: Rome’s opponents at the outbreak
The Marcomannic Wars opened in 166–167 with the Marcomanni under King Ballomarius (Ballomar), the Quadi, and the Sarmatian Iazyges launching Danube incursions. Allied groups like the Langobardi and Obii joined, but early crossings were repelled by Roman commanders Vindex and Candidus before Ballomarius led a peace embassy to the Pannonian governor M. Iallius Bassus.
At the outbreak of the Marcomannic Wars, Rome faced a coordinated push by the Marcomanni, Quadi, and Iazyges, with Ballomarius fronting a multi-tribal coalition that tested the Danube frontier. Initial raids were beaten back, yet the pressure escalated, drawing Marcus Aurelius to the Pannonian front, where he fought the Iazyges and Marcomanni in turn. The crisis deepened as bands reached into northern Italy, while the Antonine Plague thinned Roman ranks. Marcus’ own Meditations fix him “among the Quadi” and at Carnuntum, underscoring his direct command in the theater and the grueling, winter-bound campaigns that defined the war’s early phase.
Key Factors
Coalition spearheaded by the Marcomanni
Under King Ballomarius (Ballomar), the Marcomanni moved with the Quadi, Iazyges, and allies like the Langobardi and Obii to probe and cross the Danube. Early incursions were checked by Roman forces under Vindex and Candidus, after which Ballomarius headed a multi-tribal embassy to Governor M. Iallius Bassus.
Plague and post-Parthian redeployment
Fresh from the Parthian War, Rome’s forces were stretched and then ravaged by the Antonine Plague, sapping manpower and morale as the Danubian emergency unfolded. Galen describes the epidemic’s recurrence and notes its outbreak among troops wintering at Aquileia in 168/69.
Escalation into Italy and shifting leadership
Germanic thrusts reached Italy, with Opitergium destroyed and Aquileia besieged (commonly dated to 170, though debated). Cassius Dio notes Quadi leadership turmoil—Furtius deposed, Ariogaesus elevated with a bounty set on him—and records set-piece fighting on the frozen Danube against the Iazyges; the prefect Marcus Vindex fell in the fighting.
Early outcomes set the war’s pattern
Marcus campaigned from Pannonia—“among the Quadi” and at Carnuntum—pursuing winter operations and riverine warfare to break coalitions and resettle foes. The opening phase led to new legions, fortified lines, mass resettlements, and, by 175, the adoption of GERMANICUS and SARMATICUS victory titles.
Historical Evidence
"Cassius Dio reports Ballomarius (Ballomar) leading a multi-tribal embassy to M. Iallius Bassus after initial clashes, describes Germanic incursions reaching Italy, notes a bounty on the Quadi king Ariogaesus, and recounts a Roman battle against the Iazyges on the frozen Danube."
"Marcus Aurelius’ Meditations carry location headings—“Among the Quadi at the Granua (Hron)” and “Written at Carnuntum”—placing the emperor with the Danube army during the campaigns."
"The Historia Augusta highlights the siege of Aquileia and records Marcus’ intention to create the provinces Marcomannia and Sarmatia (plans unrealized)."
"Galen notes a severe, long-lasting plague and reports being present at its outbreak among troops at Aquileia in the winter of 168/69."
Part of Marcomannic Wars Begin
This entry anchors the opening phase of the Marcomannic Wars Begin (166) on the Roman Germanic Wars timeline, identifying the principal opponents and why Rome struggled early. Link from here to campaign narratives, the Aquileia crisis, and Marcus Aurelius’ counteroffensives for continuity.
More Questions About Marcomannic Wars Begin
Why did the Marcomannic Wars begin in 166 CE?
A Danube crossing by 6,000 Langobardi and Obii in late 166 CE triggered the Marcomannic Wars. Repulsed by Roman detachments, the raid snowballed into a wider Marcomanni–Quadi–Sarmatian coalition just as Rome’s frontier was weakened by troop redeployments from the Parthian War and the onset of the Antonine Plague.
Marcus Aurelius on the Danube: the opening campaigns, 166–168
In late 166 CE, a Langobardi–Obii raid across the Danube was crushed by Roman forces, prompting envoys led by Ballomar to sue for peace. In 168, Marcus Aurelius and Lucius Verus advanced to Aquileia, raising emergency levies amid the Antonine plague to prepare for a protracted Germanic and Marcomannic war.
Winter warfare on the Danube: crossings and fortified camps in 166–168
Between 166 and 168 CE, Rome fought a winter defensive war on the mid-Danube, repelling small crossings and consolidating fortified winter quarters at Carnuntum. Marcus Aurelius used Pannonia as his base, restricted frontier markets, and in 168 with Lucius Verus secured Italy and Illyricum—stabilizing the line before later river offensives.
How did the Antonine Plague set the stage for the Marcomannic Wars?
By crippling Rome’s manpower and finances just as Germanic and Sarmatian groups crossed the Danube, the Antonine Plague turned a frontier breach into a protracted war. Contemporary writers record depleted legions, delays at the capital, and emergency sales of imperial treasures—conditions that framed the Marcomannic Wars from 166.
Sources
- [1] Cassius Dio, Roman History, Book 72 (Epitome)
- [2] Cassius Dio, Roman History index (LacusCurtius)
- [3] Historia Augusta, Life of Marcus Aurelius (Loeb), parts 1–2
- [4] Marcus Aurelius, Meditations (MIT Classics), Book headings
- [5] Galen, On Avoiding Distress (Peri Alypias), NCBI Bookshelf
- [6] Numismatic attestation of SARMATICVS (AD 175)
- [7] Meditations commentary on location headers (Wikisource)
- [8] Marcomannic Wars overview (incl. Aquileia date debate)
- [9] Antonine Plague (overview and Aquileia outbreak)
- [10] Historia Augusta, Life of Marcus Aurelius, ch. 24.5
- [11] De Imperatoribus Romanis: Marcus Aurelius (war aims/provincialization)
- [12] Cassius Dio 72 (settlement of tribes; Ravenna ban)