ROMAN EMPIRE, LATER. The reign of Constantine the Great forms the most deep-reaching division in the history of Europe. The external continuity is not broken, but the principles which guided society in the Greek and Roman world are replaced by a new order of ideas. Emperor-worship, which expressed a be lief in the ideal of the earthly empire of Rome, gives way to Christianity; this is the outward sign that a mental transforma tion, which we can trace for 30o years before in visible processes of decay and growth, had reached a crisis.
Besides the adoption of Christianity, Constantine's reign is marked by an event only second in importance, the shifting of the centre of gravity of the empire from the west to the east by making Byzantium a second capital, a second Rome. The founda tion of Constantinople (q.v.) determined the subsequent history of the State; it established permanently the division between the eastern and western parts of the empire—a principle already intro duced—and soon exhibited, though not immediately, the pre ponderance of the eastern half. The eastern provinces were the richest and most resourceful, and only needed a Rome in their midst to proclaim this fact ; and further, it was eastward that the empire fronted, for here was the one great civilized State with which it was in constant antagonism. Byzantium was refounded on the model of Rome, had its own senate, and presently a prae fectus urbi. But its character was different in two ways : it was Christian and it was Greek. From its foundation New Rome had a Christian stamp ; it had no history as the capital of a pagan em pire. There was, however, no intention of depressing Rome to a secondary rank in political importance; this was brought about by the force of circumstances.
The Christian Roman empire, from the first to the last Con stantine, endured for 1,130 years, and during that long period, which witnessed the births of all the great modern nations of Europe, experienced many vicissitudes of decline and revival. In the 5th century it lost all its western provinces through the expansion of the Teutons; but in the 6th asserted something of its ancient power and won back some of its losses. In the 7th it was brought very low through the expansion of the Saracens and of the Slays, but in consequence of internal reforms and prudent government in the 8th century was able before the end of the 9th to initiate a new brilliant period of power and conquest. From
the middle of the II th century a decline began; besides the per petual dangers on the eastern and northern frontiers, the empire was menaced by the political aggression of the Normans and the commercial aggression of Venice ; then its capital was taken and its dominions dismembered by Franks and Venetians in 1204. It survived the blow for 25o years, as a shadow of its former self.
During this long life its chief political role was that of acting as a defender of Europe against the great Powers of western Asia. While it had to resist a continuous succession of dangerous enemies on its northern frontier in Europe—German, Slavonic, Finnic and Tatar peoples—it always considered that its front was towards the east, and that its gravest task was to face the Powers which suc cessively inherited the dominion of Cyrus and Darius. From this point of view we might divide the external history of the empire into four great periods, each marked by a struggle with a different Asiatic power : (I) with Persia, ending c. 63o with the triumph of Rome; (2) with the Saracens, who ceased to be formidable in the century; (3) with the Seljuk Turks, in the rrth and 12th centuries; (4) with the Ottoman Turks, in which the Roman power went down.
Mediaeval historians, concentrating their interest on the rising States of western Europe, often fail to recognize the position held by the later empire and its European prestige. Up to the middle of the iith century it was in actual strength the first Power in Europe, except in the lifetime of Charles the Great, and under the Comneni it was still a power of the first rank. But its political strength does not express the fullness of its importance. As the heir of antiquity it was confessedly superior in civilization, and it was supreme in commerce. Throughout the whole period (to 1204) Constantinople was the first city in the world. The influence which the empire exerted upon its neighbours, especially the Slavonic peoples, is the second great role which it fulfilled for Europe—a role on which perhaps the most speaking commentary is the doctrine that the Russian Tsar was the heir of the Roman Caesar.