On average, lead levels in children’s blood at the peak of the Roman empire could have risen 2.4 micrograms per decilitre, the researchers found, reducing their IQ by 2.5 to three points.

This story appears in the January/February 2017 issue of National Geographic History magazine. The emperor Hadrian was well known for building monuments across the Roman Empire, a territory that ...

Traditionally, Roman society was extremely rigid. By the first century, however, the need for capable men to run Rome’s vast empire was slowly eroding the old social barriers. The social ...