The Marcomanni are invading northeastern Italy at…

The Iazyges defeat and kill Marcus Claudius Fronto, Roman governor of Lower Moesia, in 170.

Operating from Sirmium (today Sremska Mitrovica, Vojvodina, Serbia) on the Sava river, Marcus Aurelius moves against the Iazyges personally.

After hard fighting, the Iazyges are pressed to their limits.

However, while the Roman army is entangled in this campaign, making little headway, several tribes use the opportunity to cross the frontier and raid Roman territory.

The Costoboci cross the Danube, ravage Thrace and descend the Balkans.

Bet Sh'ean becomes in 170 the new center of Jewish learning under Judah ha-Nasi, who is known simply as Rabbi.

Christians in about 170 accuse the Jews of deicide after Melito, Bishop of Sardis, publishes On the Passion, a sermon in which he blames the Jews for the persecution and death of Jesus and absolves Pontius Pilate and the Romans from any guilt, despite much evidence to the contrary.

Melito's position serves to rid the Romans of any responsibility or shame and thus encourages them to convert.

Ptolemy dies in about 170, leaving, in addition to his Geography and the earlier Almagest, three minor works: Apotelesmatika, in which he records astrological ideas from Enuma Anu Enlil; Tetrabiblos, in which he deals with astrology, and the Optics, in which he deals with reflection and refraction.

Galen of Bergama authors several hundred works (eighty of which are extant) on medicine and healing and, through experiments upon animals, founds the science of physiology.

A Greek philosopher and physician from Asia Minor who serves the emperor Marcus Aurelius, strongly influenced by Aristotle and Hippocrates’ beliefs in vital essences, Galen, though possessing practical knowledge of the circulatory system, postulates the transport of blood through vessels to the skin, where it becomes flesh.

Maintaining that knowledge of human anatomy is fundamental for a physician, he obtains anatomical facts from the dissection of animals such as pigs, dogs, and goats.

Prevented by law and custom from working with human bodies, Galen’s work, although notable, incorporates many errors when applied to human anatomy.

He nevertheless identifies numerous muscles for the first time and demonstrates the importance of the spinal cord, recording the resulting paralysis when the cord was cut at different levels.

The first to consider the pulse a diagnostic aid, he also explains the function of many nerves, discovers the sympathetic nervous system, and details almost all the structures of the brain visible to the naked eye.

His physiological theories include concepts of blood formation, digestion, and nerve function (but his insistence that tiny pores exist in the heart through which blood passes from the right to the left ventricle is an error that will be accepted throughout Europe for more than a thousand years).

Galen is an enthusiastic advocate of the virtues of opium; his books become the supreme authority on the subject for hundreds of years.

Galen had gone to Rome in 162 and had made his mark as a practicing physician.

His impatience has brought him into conflict with other doctors and he feels menaced by them.

His demonstrations here had antagonized the less able and original physicians in the city.

They plotted against him and he, fearing he might be driven away or poisoned, had left the city.

The Antonine Plague, named after Marcus Aurelius’ family name of Antoninus, is also later known as the Plague of Galen and holds an important place in medicinal history because of its association with Galen, who had first hand knowledge of the disease.

He was in Rome when it stuck in 166, and is also present in the winter of 168–69 during an outbreak among troops stationed at Aquileia.

Marcus Aurelius and his colleague Lucius Verus were in the north fighting the Marcomanni.

During the autumn of 169 CE when Roman troops were returning to Aquileia, the great plague had broken out and the emperor had summoned Galen back to Rome, ordering him to accompany Marcus and Verus to Germany as the court physician.

In the following spring Marcus is persuaded to release Galen after receiving a report that Asclepius, the god of medicine and healing in ancient Greek religion, is against the project.

He is left behind to act as physician to the imperial heir Commodus.

It is here in court that Galen writes extensively on medical subjects.

Ironically, Lucius Verus died in 169, and Marcus Aurelius himself will die in 180, both victims of the plague.

Marcus, after the death of Verus, will personally lead the struggle against the Germans for the great part of the life remaining to him.

The most important and dangerous invasion of 170 is that of the Marcomanni in the west.

Their leader, Ballomar, has formed a coalition of Germanic tribes that cross the Danube and win a decisive victory over a force of twenty thousand Roman soldiers near Carnuntum.

Ballomar then leads the larger part of his host southwards towards Italy, while the remainder ravage Noricum.

The Marcomanni raze Opitergium (Oderzo) and besiege ...

...Aquileia, the main Roman city of northeast Italy.

This is the first time hostile forces had entered Italy since 101 BCE, when Gaius Marius defeated the Cimbri and Teutones.

The army of Furius Victorinus, one of the two praetorian prefects, tries to relieve the city, but is defeated and its general slain.

Rome, in a bid to ease conflict in the upper Danube region, allows some German tribes to settle within the Empire in 171.