Europe 170: First Marcomannic War
While Rome was preoccupied with Parthia and the Antonine plague, the Germanic and Danubian tribes apparently formed a secret alliance under the leadership of the Marcomanni. In the winter of 166–167 the Langobards raided across the Danube, after which the Iazyges attacked Dacia and the Marcomanni invaded as far as Aquileia in northern Italy. Marcus Aurelius and Lucius Verus scrambled to deal with these new threats, but had only succeeded in securing Italy by the time Verus died of the plague in 169. Seizing their opportunity, the Roxolani and Costoboci joined the war in 170, with the latter advancing to Greece and sacking the sacred town of Eleusis.
12 Oct 166 End of Lucius Verus’ Parthian War▲
In mid-166 Lucius Verus ordered the Roman withdrawal from Parthia, appointing Avidius Cassius as governor of Syria. The Romans retained the strategic cities of Dura-Europos and Nisibis in northern Mesopotamia, and restored Armenia and Osroene as client states. Back in Rome, Verus celebrated his triumph in October.
? ?? 166–5 May 167 Langobard invasion of Pannonia▲
In the winter of 166–167, six thousand Langobards and Ubii invaded Pannonia, presumably via the lands of the Quadi, while a contingent of Chatti attacked Raetia. Swiftly defeated by the Romans, the invaders sued for peace with the mediation of King Bellomarius of the Marcomanni. No further records of the Langobards exist until the fourth century; according to tradition they were subjugated by the Saxons.
29 May 167–? ?? 171 Iazygan War of 167–71▲
While the Romans were negotiating their truce with the Langobards, the Iazyges attacked the gold mines of western Dacia, killing the Roman governor. More concerned by the Marcomannic threat to Italy, Marcus Aurelius paid off the Iazyges in the winter of 169–70 but later in 170 they attacked again, killing the veteran general Marcus Claudius Fronto in battle. Still more concerned with the Marcomanni, the Romans made peace with the Iazyges in 171.
Jun–?? 167 Great Marcomannic Raid▲
In the late 160s the Marcomanni and the Quadi became increasingly hostile towards Rome, apparently conspiring with the other German and Danubian tribes. In 167 they swarmed across the border, destroying a Roman army at Carnuntum and passing through the Alps into Italy—the first foreign invaders to do so since the Cimbri and Teutones (101 BC). Unable to capture the rich but fortified city of Aquileia, the Marcomanni were forced out by the Romans later in the year. (170 is traditionally given as the date for this raid, but many historians now consider that Marcus Aurelius’ movement to Aquileia and fortification of the Alpine passes in 168 was in response to this raid, making 167 more likely.)
170 Chatti War of 170▲
In 170 the Chatti crossed the Rhine, invading the Roman provinces of Upper Germania and Belgica. They were repelled by governor Didius Julianus, but Marcus Aurelius considered the issue serious enough to dispatch his son-in-law Claudius Pompeianus to the front. Pompeianus and his able field commander, Pertinax, decisively defeated the Chatti, driving them back across the Rhine.
170 Marcomannic campaign of 170▲
Roman reprisals against the Marcomanni and their allies were delayed by the plague—which killed Lucius Verus in 169—and the need to fortify the Alpine passes into Italy, but by late 169 Marcus Aurelius was ready to travel with his army to Pannonia. After securing a temporary peace with the Quadi in early 170, the emperor marched on the Marcomanni with a force of at least 100,000 troops. Somewhere across the Danube, however, the Romans were heavily defeated by the Marcomanni and Iazyges, suffering the loss of some 20,000 men and compelling Marcus to abandon the campaign.
170–171 Great Costoboci Raid▲
Taking advantage of Roman troubles in the Marcomannic War, the Costoboci, in alliance with the Roxolani, crossed the Danube into Lower Moesia in 170. Rampaging through Thrace and Macedonia, they eventually reached Achaea, where they sacked the famous shrine of the Mysteries at Eleusis. At about this point, Roman forces under Vehilius Gratus finally intercepted and defeated them, eliminating the Costoboci threat by early 171.