Taken from: Friesian.com - Third Empire, Middle Romania - Early Byzantium
Era of Diocletian 327-776, 449 years
Romania has suffered most terrible evils from the Arabs even until now.
Constantine VII Porphyrogenitus (d.959) quoting the Chronicle of Theophanes (c.815) [De Administrando Imperio, Greek text edited by Gy. Moravcsik, Dumbarton Oaks Texts, 1967, 2008, p.94]
The Constantinopolitan city, which formerly was called Byzantium and now New Rome, is located amidst very savage nations. Indeed it has to its north the Hungarians, the Pizaceni, the Khazars, the Russians, whom we call Normans by another name, and the Bulgarians, all very close by; to the east lies Baghdad; between the east and the south the inhabitants of Egypt and Babylonia; to the south there is Africa and that island called Crete, very close to and dangerous for Constantinople. Other nations that are in the same region, that is, the Armenians, Persians, Chaldeans, and Avasgi, serve Constantinople. The inhabitants of this city surpass all these people in wealth as they do also in wisdom.
Liutprand of Cremona (c.920-972), 949 AD, "Retribution," The Complete Works of Liudprand of Cremona, translated by Paolo Squatriti [The Catholic Press of America, 2007, p.50].
Once out of nature I shall never takeMy bodily form from any natural thing,
But such a form as Grecian goldsmiths make
Of hammered gold and gold enamelling
To keep a drowsy Emperor awake;
Or set upon a golden bough to sing
To lords and ladies of Byzantium
Of what is past, or passing, or to come.
William Butler Yeats (1865-1939), "Sailing to Byzantium," alluding to the mechanical birds reported at the Macedonian court.
To most people thinking of the "Roman Empire," we are well into terra incognita here. Yet in 610 the character and problems of the Roman Empire would not have been unfamiliar to Theodosius the Great. A Persian invasion was nothing new. How far it got, all the way to Egypt and the Bosporus, was. Meanwhile, the collapse of the Danube frontier was not now the doing of Germans but of Slavs and Steppe people -- the latter beginning with the Altaic Avars, whose kin would dominate Central Asia in the Middle Ages. The Persians were miraculously defeated; but before the Danube could be regained or the Lombards overcome in Italy, a Bolt from the Blue changed everything. The Arabs, bringing a new religion, Islâm, created an entirely new world, which both broke the momentum of Roman recovery and divided the Mediterranean world in a way whose outlines persist until today. Nevertheless, the Empire, restricted to Greece and Anatolia, rode out the flood. It must have been a hard nut, since the Arab Empire otherwise flowed easily all the way to China and the Atlantic. It was hard enough, indeed, that by the end of the "Third Empire" it had been in better health than any Islamic state. The promise of new ascendency, however, was brief, both for internal and external reasons. Meanwhile, there has been a cost paid, as we might expect, in prosperity and material culture. This is conspicuous in the coinage, where the previous style of low relief profile portraits is still typical in Justinian's day. However, we also start to get face on portraits, whose quality is less good. By the time of Heraclius, face on portraits are dominant, and soon exclusive, while their character ceases to be low relief and becomes cartoonish. This will improve again later, but the coinage will never have the photo-real quality that we expect in modern coinage and that was often present in the best work of the First Empire. That the gold coinage of the solidus still exists at all, however, is testimony to the fact that the prosperity and material culture of Romania never fell as far as it did in Francia.
A. The advent of Islam, 610-802, 192 years
Seldom has fortune and ability so blessed a ruler only to turn so completely against him in the end. With the Persians in Egypt, Syria, and Anatolia, the Roman Empire seemed doomed to complete collapse. Things even got worse after Heraclius arrived from Africa and seized the throne. The Persians arrived at the Bosporus and the Avars at the walls of Constantinople. But then in one of the most brilliant, but far more desperate, campaigns since Alexander, Heraclius audaciously invaded Persia itself. Confident that Constantinople was impregnable, he even wintered with the army in the field, devastating Persia, until Shâh Khusro II's own son rose up and overthrew him. The peace restored the status quo ante bellum; and Heraclius began to use the title of the defeated monarch, the traditional Persian "Great King." Thus Basileus, the Greek word for "King," became the mediaeval Greek word for "Emperor" (although, actually, Procopius was already using it that way in the days of Justinian) -- as Greek now (or hereabouts) replaces Latin as the Court language. But then, barely eight years after this exhausting victory, the Arabs, united by Islâm, appeared out of the desert and quickly conquered Syria, Palestine, and Mesopotamia. Jerusalem would never be recovered, except temporarily by the Crusaders. Old and ill, Heraclius had to watch his life's work largely melt away, while people said it was the Judgment of God because he had married his niece. But a core for the Empire had been saved.
Constans II was the last Emperor to campaign in northern Italy and visit Rome as an Imperial possession (later the Palaeologi went to beg for help). He was also the last to exert real control over the Popes, arresting Martin I (649-653, d.655) and exiling him to the Crimea.Under Constans the structure of the Roman Army was fundamentally changed to deal with the new circumstances of the Empire. As the traditional units, largely familiar from the 5th Century, fell back from the collapsing frontiers, they were settled on the land in Anatolia, to be paid directly from local revenues instead of from the Treasury, whose tax base from Syria and Egypt had disappeared. The areas set aside for particular units became the themes, which remained the military bedrock of Romania until the end of the 11th century and soon replaced the old Roman provinces as the administrative divisions of the Empire. Thus, the Army of the East, driven out of Syria, was settled in the Anatolic Theme, where it would guard the obvious route for invasion or raids from Syria: the Cilician Gates through the Taurus Mountains. Although invasions and raids there would be, the Arabs never did secure any conquests beyond the Gates. Where the Army of the East in the Late Empire numbered about 20,000 men, the forces of the Anatolic Theme varied from about 18,000 in 773 to 15,000 in 899 [Warren Treadgold, Byzantium and Its Army, 284-1081, Stanford, 1995, p.67].
As the remnants of the Late Roman Army were settled on the land (like the earlier Limitanei), there were also standing forces that accompanied the Emperor, like the old Comitatenses. There was already one such unit in the Late Empire, the Scholae. This would grow into a new Standing or Mobile Army, the Tagmata. Eventually the Tagmata consisted of the Scholae, the Excubitors, the Hicanati, the Numera, the Optimates, the Walls, the Watch, and, finally, the Varangian Guard. In 899, the Tagmata together numbered about 28,000 men, while the entire Army, Themes and Tagmata combined, added up to about 128,000 men [Treadgold, op.cit.]. This was less than half of the Augustan Army and not even a quarter of Constantine's; but considering that the Empire is reduced to the lower Balkans and Anatolia, it is proportionally still robust, especially in an Age when a paid military establishment was impossible in most of Europe. As with the decline of the Limitanei, the late Macedonian Emperors began to neglect the Thematic forces and rely on the Tagmata, which soon filled with mercenaries. Some mercenaries could be quite faithful, like the Saxon refugees from Norman England who served in the Varangian Guard for a couple of centuries (the Egklinovaraggoi). This worked reasonably well while there was money. But when the finances collapsed, loses could not be made good, or the more mercenary warriors retained. This led to fiascoes like the hire of the Catalan Company (1303), who mutinied (1305) and seized the Duchy of Athens (1311). Even under the Palaeologi, landed frontier forces (now the akritai) remained the best investment but were imprudently neglected, with disastrous consequences.
After Constantine IV withstood the first Arab siege of Constantinople, burning the Arab fleet with the famous and mysterious "Greek Fire" (which sounds like nothing so much as napalm, since it could burn under water), it looked like the Empire would survive. With the last member of the dynasty, Justinian II, we have a curious experiment in humanity. When the Emperor was deposed in 695, instead of being killed, his nose was cut off. Hence his epithet, Rhinotmetus, "Cut Nose." It was expected that this would disqualify him from attempts at restoration. It didn't, and Justinian returned to power in 705. Henceforth, deposed Emperors, or other politically threatening persons, would be blinded. This was more effective (although the blind Isaac II was restored by the Fourth Crusade), though now it may not seem particularly more humane than execution. Otherwise, the end of the dynasty demonstrates one drawback of the new themes: they represented such military force that the strategus, their commander, was continually tempted to revolt. This problem was soon addressed simply by dividing the themes into smaller ones.