Emona: A genetic snapshot of a Roman colony in Slovenia

The Roman Empire lasted for over a millennium and spanned across large parts of Europe, the Middle East and northern Africa. It has been the focus of extensive historical and archeological research. The newly emerged field of paleogenetics, made possible by extracting ancient hereditary material, called DNA, from skeletons, has made the genetic research of the Roman Empire possible. Previous research led by our team has focused on the broad genetic structure of human populations in Europe, Africa and the Middle East during Roman antiquity, giving us a first glimpse of the genetic complexity of this time. This new research project will focus on one Roman colony, Emona, built where modern-day Ljubljana stands today. By examining a single Roman colony, we will be able to gain a deeper understanding of the complexities of an urban settlement while making use of the substantial existing archeological, osteological and historical data for Emona. The Romans built many colonies, which were strictly administered and contained Roman citizens as well as indigenous and immigrant residents. Emona was an established Roman colony by 14 common era (CE), inhabited by northern Italian merchants, legionaries of the Pannonian legions and indigenous populations. It was a strategic show of power along the border of Italy and its provinces, located at the important geographic point where the Alps give way to the Danubian plain. After an economic decline in 150 CE, the colony resurged in 250 CE. By 450 CE, the colony was mostly abandoned. With well over 3000 excavated graves, Emona allows us to reconstruct the social dynamic of this Roman city. This study will examine the genomes of 300 inhumation graves from 250-450 CE to examine five main research questions: First we will examine the ancestries of the population of Emona to understand who lived in this colony. Second we will assess if there is a bias in ancestries of men and women, an effect that could occur from e.g. soldiers from far parts of the Empire producing progeny with local women. Third, we plan to examine potential associations of ancestry and archaeological mortuary contexts by collaborating with archeological experts from Emona. Fourth we will give special focus to grave groupings from the later antiquity time to assess potential familial relationships and lastly, we will determine if Emona experienced population continuity during the last 300 years of its existence or if influxes of new residents from other parts of the Empire changed the genetic make-up of Emona over time. Our work will give the first in depth look at the genetic complexity of a Roman urban settlement and will lay the groundwork for further comprehensive studies of the Roman Empire.

Emona, a Roman city strategically positioned between Italy and neighboring provinces, played a crucial role in both stable and turbulent times. To understand the diverse population of this ancient urban center, we delved into its genetic makeup using advanced techniques on ancient bones. Our focus was on the later Roman Empire, specifically the years 250-450 CE, a period marked by economic growth, military events, and the spread of Christianity and other eastern religions within the city. We discovered that Emona was a diverse melting pot where people with varied ancestry coexisted. The genetic background of ancient Emonans ranged from northern Africa to northern Europe, with a majority having connections to present-day Balkan and north Italian ancestries. Interestingly, our data suggests that in earlier times, there was a higher influx of males from outside provinces, while in later periods, both males and females from diverse backgrounds were immigrating. In the later years of Emona, burials took on a familial appearance, though we didn't find tightly-knit family groups. Instead, a central core of graves exhibited a degree of relatedness, and surrounding graves shared similar ancestries. This suggests a shift in burial practices, possibly reflecting changes in family structures or social dynamics. Our findings provide a glimpse into significant population movements and shifts in urban Roman centers. They also raise intriguing questions for future research, encouraging exploration of similar patterns in other Roman colonies.