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  • Writer's pictureNick Holmes

Constantinople and the Crisis of the Third Century

Constantinople was founded by the emperor Constantine on 11 May, 330 as the “New Rome”. It was a crucial turning point in history. But why did it happen?

Let’s start with the background. In the fourth century AD, the Roman Empire was still the greatest power on the planet. However, it had changed from the empire that we know and love, as represented in so many films and books from Ben Hur to Gladiator. By AD 330, the city of Rome itself had been abandoned as the capital of the empire. It still fielded a senate but real political power resided wherever the emperor and his army were. And the emperors no longer lived lives of luxury on the Palatine Hill above the Colosseum. Instead, they were on the front line leading the Roman army. And there were lots of co-emperors. Diocletian (who reigned from AD 284 to 305) introduced a new political system of four co-emperors called the Tetrarchs, with each one defending their bit of the empire. The emperors were now based along the frontiers, for example in Milan in northern Italy, or Trier in Germany, or Nicomedia in modern day Turkey. And if this wasn’t enough change already, there was a new religion called Christianity which was rapidly replacing the old Roman gods.

So, you may well ask what on earth had happened??

The answer lies with a crucial period in Roman history that is almost never discussed. This was the ‘crisis of the third century’ which lasted for about fifty years, from around AD 235 to 285. It very nearly marked the end of the Roman Empire. There were external and internal reasons for this. The external ones were first, a new dynasty that seized power in Persia called the Sasanians, who were very warlike and re-modelled the Persian army into an efficient fighting force that destroyed several Roman armies, capturing the Emperor Valerian in 260, and overrunning much of the east. Second, the Germanic tribes along the long Rhine and Danube frontiers also re-organised themselves into larger, more formidable tribal groups and overran much of Gaul and the Balkans. They even came close to sacking Rome, and they did sack Athens, Ephesus and numerous Roman cities and towns in Europe.

There were various internal reasons for the Roman collapse. The problems began with the first pandemic in human history, called the Antonine Plague, which was probably smallpox. This devastated the entire ancient world from AD 165 to 180, causing depopulation and economic decline. This and the growing pressures from the Persians and Germans then resulted in a military collapse. The Roman army had already lost its competitive edge by the third century, since the massed ranks of legionaries were no longer the highly disciplined and capable soldiers they had been under Julius Caesar. In the third century, they were swept aside by the Persian heavy cavalry and the huge numbers of Germanic foot soldiers.

Military defeat caused an economic and political collapse. In particular, the Roman state was bankrupted by a fall in tax revenues caused by the loss of territory to the barbarians, the decline of trade and the sky-rocketing cost of the army. Indeed, in this time of crisis, the demoralised soldiers started to take control of matters by appointing their own emperors themselves, often different ones in the east from the west. This resulted in civil war, further weakening the empire so that by 260, it had been effectively reduced to only Italy and north Africa.

So, just how did the Romans survive?

Most people at the time thought it wouldn’t. But the Romans got lucky. Through the efforts of a series of quite remarkable emperors - Aurelian, Diocletian and Constantine - they defeated the Germans and the Persians and restored the empire to what it had been. The key difference was that these emperors were quite different from any of their predecessors. They all came from Illyria, which was a Roman province today located in modern Croatia, Serbia and the territory south of the Danube excluding Greece and Bulgaria. They were not senators so they were not privileged. Indeed, Aurelian and Diocletian (but not Constantine) were the sons of peasants. What made them unique in Roman history was that they were extremely competent professional soldiers who had risen from the ranks. This was a political revolution. Further revolutions followed - the army was re-organised into a more professional force by Aurelian. Discipline was restored. The legionaries still constituted the bulk of the troops but cavalry became the new strike-force and the elite of the army. Diocletian went further by completely overhauling the Roman tax system so that tax revenues were sufficient to pay for a larger and better army. He re-modelled politics by introducing the tetrarchy - the co-rule of four emperors, two senior, two junior - who worked together to defend the frontiers.

Then Constantine took matters even further. He converted to Christianity, which had been growing in popularity as the crisis of the third century turned people against the traditional Roman gods and values. Finally, he even moved the capital to Constantinople, confirming once and for all that Rome and Italy were no longer the heart of the empire.

So, the founding of Constantinople marked the culmination of this revolution which brings us neatly back to our starting point.

But why do so few people ever talk about this crisis of the third century that transformed Rome more than any other event in its history? The main reason is that there are pitifully few surviving records. Roman history is so rich in its literary legacy that historians are naturally drawn to studying Tacitus, Livy, Plutarch and the many other great Roman writers. But they all lived before the crisis of the third century! The third century is a dark age in terms of literary sources, or indeed any sources. The fourth and subsequent centuries would see great Roman writers re-emerge, like Ammianus Marcellinus, Zosimus and Procopius, but the third century has always remained under-researched and under-emphasised.

However, don’t despair since if you’re interested in this forgotten age, then you can find out more about it - or at any rate what little we do know about it - in my podcast The Fall of the Roman Empire, and I will also have a book out in July 2022, looking at precisely this subject, called The Roman Revolution.

Oh and sorry, I forgot to say there’s a map of the city at the bottom of this page! It depends how familiar you are already with Constantinople but the first thing to look at is the multitude of buildings in the eastern tip of the city - that’s the right hand side of the map. You can see that there was an imperial palace, a couple of churches, a hippodrome and two forums. This was the heart of the ancient city. Constantine adapted the hippodrome from an earlier one that had been built by Septimius Severus over a hundred years before. Because chariot racing replaced gladiatorial combat as the main spectator sport in late antiquity, the hippodrome became the popular centre of the city. It was adorned with spectacular trophies such as an Egyptian obelisk, and the four beautiful bronze horses that were stolen by the Venetians in the Fourth Crusade and are now located in St Mark’s Basilica in Venice. In fact, the hippodrome (which has largely disappeared from view today although some impressive fragments remain) was the only tangible remnant that we have from Constantine’s original Constantinople. This is because the two churches - Hagia Sophia and Eirene - were burnt down in the sixth century and rebuilt by the emperor Justinian. In fact, what we can see today, and which remained largely intact for over a thousand years, was Justinian’s Constantinople, not Constantine’s.

Two other landmarks (and we could discuss many more) are first, the Church of the Holy Apostles in the middle of the city. This is often forgotten because it was totally destroyed by the Turks when they captured the city. But for Constantine, it was the most important church that he build because it was his mausoleum. His body lay there in a vast porphyry sarcophagus.

The other main landmark to notice is of course the walls. You’ll see that there are two sets of walls. Constantine’s walls were the first to be built and almost nothing of them survives. But the Theodosian walls, built nearly a hundred years later, still survive remarkably well in modern Istanbul. This is because they were gigantic.

They were also probably the most important defensive system in the history of the world because they saved Constantinople from the Huns, the Persians and the Arabs during three hundred years of turbulent history. Indeed, it could be argued that without them, the eastern Roman Empire would have gone the way of the western empire. Indeed, if they had not withstood the Arabs, it is conceivable that Islam would have conquered Europe or at least a major part of it. In short, they were game-changers in history.

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