173

173 was the 173rd year of the Christian era (abbreviated AD or CE), part of the second century. During this year, the Roman Empire was under the rule of Marcus Aurelius, who reigned as emperor of Rome from 161 to 180.

In the earlier Roman system of dating, years were designated by the names of the two consuls holding office that year, rather than by numbers. The "AD" system of numbering years began centuries later, after the work of Dionysius Exiguus in the sixth century, and was subsequently adopted systematically throughout Europe.

Condition of the Roman Empire

In the years around 173, Marcus Aurelius spent considerable time at the northern frontier along the Danube River, where he fought wars against the Marcomanni, Quadi, and related tribes. These campaigns are known collectively as the Marcomanni Wars. During the same period, the empire was afflicted by a widespread plague (which historians call the Antonine Plague), which affected population numbers and military strength.

East and other regions

The Han Empire of China still existed at this time, though political and economic changes were beginning within. South Asia and the Horn of Africa participated in Red Sea and Indian Ocean trade, which supplied goods to Roman markets.

Religion and thought

The second century is marked by the spread of Christian communities in the major cities of the Roman Empire, and by writers defending their beliefs against Roman opposition. Stoic philosophy also held considerable influence, with Marcus Aurelius himself authoring a well-known book of philosophical reflections.