Although the history of Imperial Rome is well documented through architecture, art, and literature, the bulk of this only accounts for the wealthy, the powerful, and the literate.

However, a new bioarchaeological study has given an insight into a very under-represented class: the poor migrant. Through tracing the skeletons' biochemical make-up, the study says they can track the migrants' origin and give an insight into their experience of life in the Roman Empire.

The findings of the study, conducted by researchers from the University of West Florida and Durham University, were recently published online in PLOS ONE.

The archeological dig excavated 105 human skeletons from two cemeteries in Rome, in the neighborhoods of Casal Bertone and Castellaccio Europarco. Among the boney bounty, they discovered at least eight of the individuals were likely to have been male immigrants.

^{The location of Casal Bertone and Castellaccio Europarco, the two burial sites uncovered. Kristina Killgrove.}

The skeletons are thought to have come from either the Alps or North Africa, sometime between the first and third century C.E.

Using a three-pronged attack of analyzing the ratios of oxygen, strontium, and carbon variants, or isotopes, in the skeletons' teeth, the researchers believe they have been able to get insights into the geographical origins of the skeletons, as well as some sense of their lifestyles.

Strontium gives a good indication of geographical origin, as it makes its way into the body through food and drinking water from the weathering of rocks. This is particularly useful, as rocks can be very specific to a region or indicative of a certain time period. Oxygen isotopes are related to the qualities of drinking water and can vary because of factors like a place’s rainfall, humidity, temperature, elevation, latitude, and even distance from the coast.

As such, an individual with strontium or oxygen isotope ratios in line with the water, soil, and rocks in the region are expected to have been born locally. But if the ratios differ, they are expected to have been from elsewhere when their teeth were growing and incorporating these chemical records.

Four of the skeletons were found to have exceptionally high strontium isotope ratios, hinting that they came from a place of older geology, such as the Alps or Mediterranean Islands like Corsica or Sardinia. One of the skeletons had particually high oxygen and low strontium isotope ratios, suggesting an origin in a region of limestone or basalt with a hotter, drier climate than Rome, such as North Africa.

Buried in close proximity, and with seemingly minimal ceremonial markings, the migrants are thought to have been poor and of low social status. As lead researcher Dr. Kristina Killgrove explained to the Mail Online, it's likely that the migrants came to Rome as involuntary slaves or to find work, as opposed to migrating for marriage or education, which would suggest they were wealthy. 

The findings also suggest that the migrants changed their lifestyle once they arrived in Rome. Data gathered from the teeth suggests that they ate a typical Roman diet, composed largely of wheat along with smaller amounts of legumes, meat, and seafood. When in Rome, I guess.

The authors hope to conduct DNA analysis and more isotopic analysis to further hone in on their suggestions. The fine art of bioarchaeology is still findings its feet, meaning many of these points made by the archeologists are speculative. Nevertheless, as technology advances and processes become more refined, this idea of linking biochemistry with history holds many exciting prospects.