Dr. David Gwynn

But when you're trying to protect a very wide frontier, more smaller groups work more easily. So one feature that seems to emerge with Diocletian and Constantine is you get an increase in the number of legions, which used to be argued to mean, oh, look, the army's getting much bigger.

But when you're trying to protect a very wide frontier, more smaller groups work more easily. So one feature that seems to emerge with Diocletian and Constantine is you get an increase in the number of legions, which used to be argued to mean, oh, look, the army's getting much bigger.

But what the archaeology of the army camp suggests is that the legion size dropped from around 5,500 to more like 1,000. Wow. That's like four-fifths of the strength gone. So in reality, you've still got the strength because the number of legions is dramatically multiplying. But you've got smaller blocks because that way you can spread out across the frontiers.

But what the archaeology of the army camp suggests is that the legion size dropped from around 5,500 to more like 1,000. Wow. That's like four-fifths of the strength gone. So in reality, you've still got the strength because the number of legions is dramatically multiplying. But you've got smaller blocks because that way you can spread out across the frontiers.

But what the archaeology of the army camp suggests is that the legion size dropped from around 5,500 to more like 1,000. Wow. That's like four-fifths of the strength gone. So in reality, you've still got the strength because the number of legions is dramatically multiplying. But you've got smaller blocks because that way you can spread out across the frontiers.

Not least because the earlier empire of the first, second century wasn't so focused on frontier defense. It was more about when do you advance beyond the frontiers? Whereas in the third century crisis, they were reacting. They had to react.

Not least because the earlier empire of the first, second century wasn't so focused on frontier defense. It was more about when do you advance beyond the frontiers? Whereas in the third century crisis, they were reacting. They had to react.

Not least because the earlier empire of the first, second century wasn't so focused on frontier defense. It was more about when do you advance beyond the frontiers? Whereas in the third century crisis, they were reacting. They had to react.

How far the Romans were actually ever clear-cut dominant is one of those interesting questions. The Romans lose a remarkable number of major battles in their history. Famously, the Roman Republic has a remarkable ability to lose battles. The Pyrrhic War, they lost two, won one. Fighting Hannibal, lose three, win one. The pattern's consistent.

How far the Romans were actually ever clear-cut dominant is one of those interesting questions. The Romans lose a remarkable number of major battles in their history. Famously, the Roman Republic has a remarkable ability to lose battles. The Pyrrhic War, they lost two, won one. Fighting Hannibal, lose three, win one. The pattern's consistent.

How far the Romans were actually ever clear-cut dominant is one of those interesting questions. The Romans lose a remarkable number of major battles in their history. Famously, the Roman Republic has a remarkable ability to lose battles. The Pyrrhic War, they lost two, won one. Fighting Hannibal, lose three, win one. The pattern's consistent.

You lose, but you win the last one and come out still standing. You keep coming back. Exactly. The Romans always had that strength. And in many ways, that's their greatest military advantage. It's not utter brilliance on the battlefield. It's not a clear-cut technological advantage.

You lose, but you win the last one and come out still standing. You keep coming back. Exactly. The Romans always had that strength. And in many ways, that's their greatest military advantage. It's not utter brilliance on the battlefield. It's not a clear-cut technological advantage.

You lose, but you win the last one and come out still standing. You keep coming back. Exactly. The Romans always had that strength. And in many ways, that's their greatest military advantage. It's not utter brilliance on the battlefield. It's not a clear-cut technological advantage.

But it is consistent technology, reserves, the ability to re-recruit armies, retrain them, bring them back into the field. The third century crisis, they had to make it up as they were going along. The Romans had never come under this level of pressure before. The Persians, for example, used heavily armored cavalrymen, cataphracts. They don't move that fast, but they are very heavy cavalry.

But it is consistent technology, reserves, the ability to re-recruit armies, retrain them, bring them back into the field. The third century crisis, they had to make it up as they were going along. The Romans had never come under this level of pressure before. The Persians, for example, used heavily armored cavalrymen, cataphracts. They don't move that fast, but they are very heavy cavalry.

But it is consistent technology, reserves, the ability to re-recruit armies, retrain them, bring them back into the field. The third century crisis, they had to make it up as they were going along. The Romans had never come under this level of pressure before. The Persians, for example, used heavily armored cavalrymen, cataphracts. They don't move that fast, but they are very heavy cavalry.

There are tanks on there. Exactly. And the Romans don't have an obvious response to that. So how do you adjust? The Germanic tribes, which largely, of course, have the advantage of energy, enthusiasm, but aren't good at having reserves. Julian the Apostate, as described in detail by Ammianus Marcellinus, wins us basically a set piece battle.

There are tanks on there. Exactly. And the Romans don't have an obvious response to that. So how do you adjust? The Germanic tribes, which largely, of course, have the advantage of energy, enthusiasm, but aren't good at having reserves. Julian the Apostate, as described in detail by Ammianus Marcellinus, wins us basically a set piece battle.

There are tanks on there. Exactly. And the Romans don't have an obvious response to that. So how do you adjust? The Germanic tribes, which largely, of course, have the advantage of energy, enthusiasm, but aren't good at having reserves. Julian the Apostate, as described in detail by Ammianus Marcellinus, wins us basically a set piece battle.