Professor Kyle Harper

There's important things going on inside Roman society, inside the way the empire works, inside the relation between the center and the periphery, between elites and workers, geopolitically, between the Romans and the peoples across their frontier, especially across the northern frontier.

There's important things going on inside Roman society, inside the way the empire works, inside the relation between the center and the periphery, between elites and workers, geopolitically, between the Romans and the peoples across their frontier, especially across the northern frontier.

So the only question is whether those are sufficient to explain what happens, because it's not like the Romans had never faced civil conflict. In the first century, they absolutely do. I mean, in 68, 69, the empire breaks down. The system for controlling power totally melts down. And yet... The empire doesn't fall apart. It doesn't split into permanent pieces. It pretty quickly heals.

So the only question is whether those are sufficient to explain what happens, because it's not like the Romans had never faced civil conflict. In the first century, they absolutely do. I mean, in 68, 69, the empire breaks down. The system for controlling power totally melts down. And yet... The empire doesn't fall apart. It doesn't split into permanent pieces. It pretty quickly heals.

So the only question is whether those are sufficient to explain what happens, because it's not like the Romans had never faced civil conflict. In the first century, they absolutely do. I mean, in 68, 69, the empire breaks down. The system for controlling power totally melts down. And yet... The empire doesn't fall apart. It doesn't split into permanent pieces. It pretty quickly heals.

The year of the four emperors after the forced suicide of Nero, where there's no script for how you change dynasties and it's settled by force. And these kinds of conflicts are sort of at some level, always there. But you could definitely argue in the second century that there are new kinds of pressures, particularly geopolitically.

The year of the four emperors after the forced suicide of Nero, where there's no script for how you change dynasties and it's settled by force. And these kinds of conflicts are sort of at some level, always there. But you could definitely argue in the second century that there are new kinds of pressures, particularly geopolitically.

The year of the four emperors after the forced suicide of Nero, where there's no script for how you change dynasties and it's settled by force. And these kinds of conflicts are sort of at some level, always there. But you could definitely argue in the second century that there are new kinds of pressures, particularly geopolitically.

But now I think we know enough to say that there are strong clues that we ought to consider the contribution of other factors as well. So two things that I would submit we ought to think about. One is that over the second century, it's now really beyond question that the climate becomes more unstable. It doesn't mean it's necessarily going from good to bad.

But now I think we know enough to say that there are strong clues that we ought to consider the contribution of other factors as well. So two things that I would submit we ought to think about. One is that over the second century, it's now really beyond question that the climate becomes more unstable. It doesn't mean it's necessarily going from good to bad.

But now I think we know enough to say that there are strong clues that we ought to consider the contribution of other factors as well. So two things that I would submit we ought to think about. One is that over the second century, it's now really beyond question that the climate becomes more unstable. It doesn't mean it's necessarily going from good to bad.

It's not quite that simple, but it's going from relatively good and relatively stable to more unstable and probably more challenging if you're a farmer. in poor regions of the Roman Empire like Italy.

It's not quite that simple, but it's going from relatively good and relatively stable to more unstable and probably more challenging if you're a farmer. in poor regions of the Roman Empire like Italy.

It's not quite that simple, but it's going from relatively good and relatively stable to more unstable and probably more challenging if you're a farmer. in poor regions of the Roman Empire like Italy.

And so the hydroclimate, the sort of rainfall patterns which are really important for farming, they're also really complicated and they're always kind of variable and on the edge in the Mediterranean where it's arid, where water scarcity is a sort of constant concern for farmers. But in the mid to late second century, the indications are that the climate just starts to wobble more.

And so the hydroclimate, the sort of rainfall patterns which are really important for farming, they're also really complicated and they're always kind of variable and on the edge in the Mediterranean where it's arid, where water scarcity is a sort of constant concern for farmers. But in the mid to late second century, the indications are that the climate just starts to wobble more.

And so the hydroclimate, the sort of rainfall patterns which are really important for farming, they're also really complicated and they're always kind of variable and on the edge in the Mediterranean where it's arid, where water scarcity is a sort of constant concern for farmers. But in the mid to late second century, the indications are that the climate just starts to wobble more.

And I think that there's probably food shortage, even if it's not quite outright famine in the way we might see later. And that's now attested in tree rings, in marine cores, to some extent in ice cores where we do see volcanic eruptions becoming a factor again.

And I think that there's probably food shortage, even if it's not quite outright famine in the way we might see later. And that's now attested in tree rings, in marine cores, to some extent in ice cores where we do see volcanic eruptions becoming a factor again.

And I think that there's probably food shortage, even if it's not quite outright famine in the way we might see later. And that's now attested in tree rings, in marine cores, to some extent in ice cores where we do see volcanic eruptions becoming a factor again.