The multicultural Roman Empire revealed by DNA

HostI always used to look at those old white marble statues and think I knew what a Roman looked like. I pictured a specific kind of person from a specific part of Italy, but it turns out that if you could walk through a street in ancient Rome, the faces you would see might surprise you. How much has DNA changed our view of who the Romans really were?

GuestIt has changed almost everything we thought we knew about the people themselves. For a long time, we had to rely on books written by rich guys or the names carved into graves. Those tell one story, but DNA tells a much deeper one. A few years ago, a team of experts looked at the bones of people who lived in and around Rome over the last twelve thousand years. What they found was that right when Rome became a massive power, the DNA of the city shifted in a huge way. It didn't just show a few new people coming in. It showed that the city was a massive blend of folks from all over the world.

HostBut surely most of the people there were still from the local area, right? I mean, you have a city in Italy, so you would expect most of the bloodlines to stay pretty local even if the city grows.

GuestYou would think so, but the data says the opposite. During the peak of the empire, the local Italian DNA in the city of Rome was almost gone. It was replaced by people whose roots were in the East. We're talking about places like Greece, Syria, and North Africa. If you stood in the middle of a Roman market two thousand years ago, you would be surrounded by people whose families had recently come from the other side of the sea. Rome was less like a small town and more like modern New York. It was a place where everyone was from somewhere else.

HostWait, I thought the Romans were the ones doing the conquering. It sounds like you're saying the people they conquered just moved into the capital. How does that happen if the Romans were the ones in charge?

GuestIt happened because Rome was like a giant vacuum. It pulled people in for all sorts of reasons. Some came as slaves, which is a dark part of the story we have to keep in mind. Millions of people were brought to Italy against their will. But many others came because Rome was where the money and the food were. If you were a trader, a builder, or a craftsman, you went to the heart of the empire to find work. The empire built these incredible roads and kept the seas safe from pirates, which made it easy for people to move. Once you have a path from one side of the world to the other, people are going to walk it.

HostI can see traders moving around, but you said the local DNA almost vanished. That feels like a stretch. Wouldn't the local families still be the ones running things?

GuestThe ruling class might have kept their old family names, but even they were mixing. And the sheer number of newcomers was just too big. In the city of Rome itself, the group of people from the East became the biggest part of the crowd. The DNA marks from the Near East are much stronger in the bones of that time than the marks from the people who lived there before the empire started. It shows us that the empire wasn't just a map with lines on it. It was a living, breathing mix where the far edges of the world were constantly flowing into the center.

HostSo if I went to a different part of the empire, like a small town in Britain or a farm in Spain, would I see the same thing? Or was this just a big city thing?

GuestIt was mostly a big city thing, but you still see it in other spots. We have found bones of people in the north of England who grew up in the heat of North Africa. We see soldiers from the Middle East stationed on the borders of Germany. But the city of Rome was the extreme case. It was the hub. Every road led there, so every kind of person ended up there. What's really wild is that this mix wasn't just a one-time thing. It lasted for hundreds of years. For a long stretch of history, the very idea of what it meant to be Roman had nothing to do with where your grandfathers were born.

HostThat sounds like a very open way to live, but I wonder if it lasted. If the DNA changed that much, did it stay that way after the empire fell?

GuestNo, and that's one of the most telling parts of the study. Once the empire started to crumble and the central power faded, the mix started to thin out. The long-distance travel stopped because the roads weren't safe and the big trade ships stopped sailing. When the experts looked at bones from the time after the fall of Rome, the DNA started to look local again. The people from the East weren't being replaced by new arrivals anymore. The city stopped being a world hub and went back to being a place where mostly people from the nearby area lived.

HostThe DNA shows that as soon as the big world-wide web of the empire broke, the city went back to its own little corner of the world.

GuestThe bones show us that for a few hundred years, the city was a bridge that linked three whole continents together in a way that wouldn't happen again for a very long time.

HostThose marble statues in the museums might be the same color, but the faces on the streets of the capital were a mix of every shore of the Middle Sea.