After the Roman Empire’s economic collapse in the third century, it had been a rash act, on Constantine the Great’s part, to saddle the Empire, which Diocletian had just nursed into convalescence, with a duplicate capital city. This was all the more rash because, if the New Rome was to be a counterpart of the Old Rome, it, too, had to be endowed with “bread and shows” for its populace as a charge upon the whole Empire’s productive capacity – a capacity that was already being over-taxed by a steep increase in the size and cost of the Army. The provisioning of the new duplicate capital also doubled the strain on the Mediterranean merchant-marine, which now had to carry cereals from the southern shores of the Mediterranean to feed, gratis, the inhabitants of a pair of parasitic capitals.
It is true that Constantine had shown genius in his choice of the site for his new capital for the Roman Empire – though Constantine was not the first statesman to notice the felicity of Byzantium’s location. This had been recognized already, before the close of the sixth century B.C., by a sharp-sighted Persian statesman, according to a fifth-century-B.C. Greek historian. [Footnote: See Herodotus, Book IV, chap. 144, for the remark, attributed to Megabazos, that the founders of Chalcedon had been blind in overlooking the site on which Byzantium had been founded seventeen years later.] Constantinople was, indeed, far better placed than Rome for serving as the capital of a circum-Mediterranean empire in the Roman Age of the Mediterranean basin’s history.
Megabazos was one of Darius’s generals. Chalcedon was a Megaran colony. The site was obviously inferior to the one within view on the opposite shore. It was in the territory called Bithynia, which was an independent kingdom before it fell to Rome in 74 BC. Now it is the suburb of Kadıköy, south of Üsküdar, on the Asian side of Istanbul. Byzantium was founded a few years after Chalcedon, also from Megara.
Rome had been well placed for winning the hegemony over Peninsular Italy by military operations on land. But Rome’s site had become inadequate for serving Rome’s needs when Rome had taken to the sea in the First Romano-Carthaginian War, when she had gone on to win the naval command of the Mediterranean, and when she had finally brought under her rule, direct or indirect, the whole perimeter of the Mediterranean, with as much of its hinterland as could be conquered and held by Roman infantry based on the shores of the Mediterranean itself and of its backwaters. Rome had dominated Peninsular Italy thanks to her command of the lowest-down bridge over the Tiber, which was the Peninsula’s principal river, but this lowest-down bridge was too far up the river to be accessible for sea-going vessels, whether merchant-ships or warships, in the post-Alexandrine Age, when the size of ships had increased, while the lowest reach of the Tiber had been silting up. Cargoes destined for Rome had now to be transshipped into lighters that could be towed up the river, and this had to be done in the open sea till eventually – at a cost that could be met only by drawing on the public revenue of the whole Mediterranean World – an artificial port for sea-going vessels, where trans-shipment could be carried out in all weathers, had been excavated and had been linked up with the river.
This local inconvenience of Rome’s site for access by water was a serious handicap for Rome so long as communication was quicker and cheaper by water than by land, as it continued to be till the invention of railways; but Rome’s geographical position in the Mediterranean basin was a still more serious drawback for a city that had become the political capital of the Mediterranean World. Rome’s access to the sea, such as it was, opened on to the western basin of the Mediterranean, and, in the Roman Age of Mediterranean history, the western half of the Mediterranean World, including Peninsular Italy itself, was under-developed and under-populated by comparison with the contemporary development of the Levant. In that age the Levant was the Mediterranean World’s economic and demographic centre of gravity. Egypt, Syria, and western Asia Minor were the Mediterranean World’s industrial and commercial power-houses. The economic capital of the Roman Empire was not Rome-on-Tiber; it was Alexandria-on-Nile.
Constantinople was nearer than Rome to these three key Levantine regions and was also more accessible than Rome was from each of them. Julius Caesar and Augustus were believed by their contemporaries to have played with the idea of transferring the capital of their empire from Rome to Alexandria Troas or to Troy itself. These two [Asian] sites commanded the approaches from the Aegean to the Dardanelles, as well as the ferries, across the Dardanelles, between Asia and Europe. Since Augustus’s day, the main crossing between the two continents had shifted northward, by Constantine the Great’s time, from the Dardanelles to the Bosphorus, and accordingly, if the Mediterranean World was to be given a new capital on one of the two straits linking the Aegean with the Black Sea, Byzantium was now the inevitable site. Byzantium was singled out not only by its geographical location but by the local topography. Troy, like Rome, was not on the coast; Alexandria Troas had no natural harbour; Byzantium had a uniquely serviceable natural harbour in the Golden Horn, a deep-water inlet into which a ship coming from the Black Sea was wafted by the current of the Bosphorus unless its steersman deliberately set its course for the Sea of Marmara. The Golden Horn was the topographical treasure which the founders of Chalcedon had been thought by Megabazos to have overlooked.
Byzantium could be reached by sea-going ships from anywhere in the Mediterranean basin and its backwaters, and, conversely, a government seated in Byzantium could send soldiers or administrators by sea to any point on the Mediterranean coasts of the Roman Empire. Byzantium also commanded the ferries across the Bosphorus on the shortest route between the lower course of the River Danube and the middle course of the River Euphrates; and, in Constantine’s day, these were the two sections of the Roman Empire’s frontier that were under the heaviest pressure from external enemies.
This Danube-Euphrates portage is not mentioned in the passage on portages which I quoted here.
Thus by Constantine the Great’s day the site of Byzantium had become still more important strategically than it had been in Megabazos’s day, rather more than eight centuries earlier. On the other hand, the economic importance of the waterway on which Byzantium stood had diminished by the time when Constantine decided to plant his New Rome there.
In the pre-Alexandrine Age of Hellenic history, the water-route between the Aegean and the Black Sea had been one of the two main thoroughfares of the Hellenic World. It had, indeed, surpassed in economic importance the route from the head of the Gulf of Corinth across the Straits of Otranto to south-eastern Italy and Sicily. The narrow seas between the Black Sea and Aegean had been the route by which, from the seventh century B.C. onwards, the industrial and commercial Greek city-states in the Aegean basin had imported cereals from the Black Earth zone of the Ukraine in exchange for exports of Greek manufactures. The rapid increase, in and after the seventh century B.C., of the population and wealth of Corinth and the other circum-Isthmian city-states of Continental European Greece, and the corresponding contemporary development of Meletos and other city-states on the west coast of Asia Minor and on the adjoining islands, would have been impossible if their food-supply had continued to be limited to the meagre produce of their own territories. In that case they could not have made their economic revolution from the agrarian economy of the ordinary Greek city-state to an industrial and commercial economy with distant markets and sources of supply. The development of these Greek city-states was made possible by their access to sea-borne imports of grain from the Black Earth zone of the Ukraine.
The import of cereals into the Roman Empire from the north shore of the Black Sea through the Thracian Bosphorus past Byzantium had come to an end nearly a hundred years before Constantine the Great selected Byzantium as the site for his new Levantine capital of the Roman Empire. [Ended by Gothic incursions into what we call the Ukraine.] So long as this trade had survived, Byzantium had had the first refusal of the grain that had been the cargo carried by the ships on their southward voyage. “First come, first served.” If cargoes of grain had still been entering the Bosphorus from the Black Sea in Constantine the Great’s time, the creator of the New Rome would have found a food-supply for his new city ready to hand without needing to poach on the sources of supply previously drawn upon by the Old Rome. However, this deterioration of Byzantium’s once unusually favourable economic circumstances did not deter Constantine the Great from enlarging this small colonial Greek city-state into a duplicate capital for the Mediterranean World.
Even after the temporary collapse from which it was recovering in Constantine the Great’s day, the Roman Empire still had vast sources of food-production. Constantine the Great provided the bread-dole for Constantinople by diverting to the new capital the cereals exported from Egypt, leaving to the Old Rome the export from North-West Africa and Sicily. After Justinian I had reconquered the Roman Empire’s Vandal successor-state, these sources, too, of cereals were at the Constantinopolitan Roman Government’s disposal, if required, for the provisioning of Constantinople.
After Justinian I’s death in 565, his successors held, for a few years, about two-thirds of the area over which the Roman Empire had extended in 395, the date of the death of the Emperor Theodosius I. But the strain that had been put on the economy of the Empire’s previously prosperous Levantine dominions by Justinian I’s wars brought its nemesis in 602, when the Constantinopolitan Roman Empire collapsed [or when the troops, asked by Maurice to stay for winter beyond the Danube, mutinied, Phocas killed Maurice and declared himself emperor, and the last round of wars with Persia began]. The Persian occupation of Egypt in 616 suddenly cut off Constantinople’s source of food-supply, and the bread-dole was discontinued, provisionally in 618 and definitively in 626.
In this crisis, the populace of Constantinople would have welcomed even a trickle of grain from the northern hinterland of the Black Sea, but the export of grain from that quarter was not resumed, on any appreciable scale, for another twelve hundred years. In the tenth century, when Constantine Porphyrogenitus was compiling his De Administrando Imperio, Cherson (i.e. the Megarian colony Chersonesus), which by that date had been for many centuries the only surviving Greek city-state on the north shore of the Black Sea, was importing food-supplies, not from the Ukraine nor even from the Kuban basin [the Kuban flows into the Sea of Azov from the Caucasus], but from northern Asia Minor. The Chersonese were paying for this food by serving as middlemen for handling goods exported by the Pechenegs, who, in the tenth century, were the pastoral nomad occupants of the Black Sea Steppe, but the Pechenegs, unlike their long since vanished Skyth predecessors, did not export grain from the Ukraine; their exports were hides – presumably those of animals bred by the Pechenegs themselves on the Steppe – and wax, which they must have obtained, by raiding or trading, from the northern forests, but which was an unprofitable substitute for the grain that the Skyths had once drawn from the Black Earth.
Flickr credit: beside_the_seaside
Constantine Porphyrogenitus and His World, OUP, 1973