Byzantine Empire, called also the Eastern or Lower Empire, or yet oftener the Greek Empire, may be said to have taken its rise in 395 A.D., when upon the death of Theodosius the Roman Empire was divided into two parts, and shared between Arcadius and Honorius. The former established his seat of government at Constantinople, which had been founded in 330 A.D. upon the site of the ancient Byzantium, and ruled over Syria, Asia Minor, and Pontus upon the Asiatic side of the Black Sea, Egypt in Africa, and Thrace, Moesia, Macedonia, Greece, and Crete in Europe. The history of the Empire is generally divided into four periods: (1) Its growth from 395 to 716; (2) its time of prosperity from 716 to 1057 (Leo III. to Isaac Comnenus); (3) a period of decay from 1057 to 1204; (4) its decline and fall from 1204 to 1453, in which year Constantinople was taken by the Turks.
The choice of a new capital had been in a measure forced upon Constantine by his conversion to Christianity, Rome itself being the head-quarters of Paganism. No better site could have been chosen than Constantinople, which is the key of two continents and two seas, and is still a bone of contention to European powers. The new capital was Roman in nature, the privileges of its people were those of Roman citizens, and the official language was Latin, but by Justinian's time (527-565) the prevailing language of the Empire was Greek, and all the highest officers were Greeks. Of the first period above-mentioned, the best known period is that of Justinian's reign, which, though really injurious to the Empire, seemed particularly brilliant, owing both to the great legal measures which bear his name, and also to the campaigns of his generals Belisarius and Narses, which restored the shaken power of the Empire in Africa, and in Italy and Southern Spain. In his reign, too, the church of St. Sophia was built, Another marked feature of the first period was the continual irruption of barbarians, which seriously threatened the supremacy, if not the existence of the Empire; while upon the eastern side it had a formidable enemy in Persia, which indeed bade fair to overturn it at the period when Heraclius, by his campaigns and brilliant victories, saved the Empire, and gave Persian power its death-blow. But the exhaustion that followed upon these campaigns injured the Empire, since it favoured the growth of the newly-appearing power of the Saracens. At the beginning of the eighth century the Empire was in a perilous state, and seemed likely to fall, as the Western Empire had done before it, for in Europe the Bulgarians threatened it, the Saracens were overrunning the Asiatic possessions, and attacked Constantinople, and many of its provinces were lost, while rebellion and anarchy reigned at home, and the Greek race seemed in danger of being destroyed. It was at this time that Leo the Isaurian came into power, and inaugurated the second period (716-1057), the time of prosperity - a period the first century and a half of which was marked by the Iconoclastic dispute, and the remaining two were coincident with the Basilian dynasty. Leo III., with whom, in the opinion of some historians, the Byzantine Empire - as distinguished from the Eastern Roman Empire - really began, rearranged the country for military purposes, reorganised the financial system, simplified the laws, and endeavoured to reform the church - an attempt in which he was warmly seconded by his son, Constantine V., who was an ardent Iconoclast. The controversy was not entirely one simply about the use of images. Beneath it were lying the deeper issues of aggression upon liberties, and the growth of despotism. The religious question was finally set at rest in 842, in the reign of Michael III., not however till it had cost the Empire its dominions in central Italy. Two formidable enemies were at the door of the Empire - the Saracens, who were at the height of their power, and to whom, in 1045, Constantine IX. laid open his country by destroying an Armenian kingdom which had been the bulwark of the frontier; and the Bulgarians, who having founded a kingdom in Moesia had become Christians, and had gradually enlarged their territory to an extent equal to the European part of the Byzantine Empire. The Bulgarian power was however brought to an end by Basil II., and in 1018 the people submitted to the Greek power. A third enemy who appeared in this period, but who became afterwards fast friends, were the Russians, who made several bold and daring attacks upon the capital, their representatives sometimes being the Scandinavian Varangians, who at a later period formed the trusted body-guard of the Emperors. Readers of Sir Walter Scott's Count Robert of Paris will remember the Varangian Guard. It was during this period that a plague devastated the Empire, and was the cause of colonies of Slavs and Albanians being brought in to occupy the districts made vacant by those who died of the plague, or were induced to go to Constantinople to fill up the gaps caused by the plague there. Some (the Austrian historian Fallmerayer in particular) have held that owing to the number and extent of these colonies, not a drop of Greek blood is to be found in Greece at the present day. Probably, however, this view is very much exaggerated. The third period (1057-1204) extends from the accession of Isaac Comnenus to the taking of Constantinople, and is one of high civilisation but (with periods of revival) gradual decay. And yet the period of the Comneni is more familiar to us than any other, owing to the intercourse of the Crusaders with the Empire, and to the fact that the new Greeks began to have a literature, and that we have contemporary accounts of events, notably that of Anna Comnena who has described to us the Crusaders and the impression they created, and on whom Sir W. Scott has freely drawn for materials in the romance above-mentioned. Though the Crusaders arrived in the East at the invitation of the Greek Emperor, and did check the advance of the Seljuk Turks, yet they were by no means an unmixed good to the Empire, and seemed to care little whether they fought against the Saracens or plundered the Greeks. There were no doubt faults on both sides, but nothing has been shown to warrant the piratical expedition which goes by the name of the Fourth Crusade, which dismembered the Empire, and gave it a Latin dynasty, which after a few years of feeble existence was thrust off the throne by Michael Palaeologus, who, though he did his country some good, did more to hasten its ruin. He debased the coinage, killed the trade of his subjects by the privileges he granted to the Genoese and Venetians, and utterly alienated the minds of his people by consenting to the reunion of the Eastern and Western churches. For the rest of this last period the Empire languished away, while the Ottoman Turks waxed stronger and stronger, and encroached more and more upon the few remaining possessions of the Empire, till the struggle culminated in the siege of Constantinople by Mahomet II., in 1453, and its final capture, when the last Emperor died defending the breach, and his conqueror passed in over his body. A spirited and interesting account of the siege and fall of the city is to be found in the tale Theodora Phranza.