interfered between the rival patriarchs Ignatius and Photius, a rupture was very nearly occurring ; and at last, though the formal causes of division were theological, yet the assumptions of the see of Kome and political antagonisms wore in reality more influential motives. The bitterness thus created culminated in the capture of Constantinople by the Latins at the time of the fourth crusade ; and the subsequent refusal of aid by the Western nations to the Greeks greatly facilitated the success of the Ottomans. From this, the greatest breach in the Christian world, we turn with thankfulness to the missionary efforts of this age. In the middle of the 9th century two brothers, Cyril and Methodius, preached the gospel to the southern Slavonians, and converted them to Christianity. By Cyril the alphabet called Cyrillic was invented, which was generally adopted by the Slavonic peoples. About the same time the Bul garians renounced their paganism, through the influence of a sister of their king, Bogoris, who had been educated as a prisoner at Constantinople, and afterwards restored to her native country. The rest of the nation had been prepared for this change by the numerous Christian slaves who had previously been carried off by them in war. A century later Christianity was introduced by Greek influence among the Russians, whose capital was now at Kieff, and who were among the most dreaded foes of the Eastern empire. If the missionary spirit is the best evidence of the vitality of a church, it is clear that that of Constantinople, however much corrupted by formalism, was still animated by the spirit of true religion.
The Persian monarchy, which for 400 years had been the rival of the Roman power in Asia, had now succumbed to the victorious arms of the Saracens; and that people again, during the next four centuries, were engaged in almost con tinual war with the Byzantine empire. In the reign of Constantino Pogonatus, the caliph Moawyah besieged Con stantinople for seven years by land and sea, the invaders retiring to Cyzicus for the winter (672-9); but, owing in great measure to the newly invented Greek fire, he was obliged at last to desist from the attempt, and almost the whole of his force was destroyed. Notwithstanding this reverse, the attempt was renewed within a year after Leo III. s accession by Moslemah, brother of the caliph Suleiman, with an enormous host ; but the skill of the Byzantines in military defence, which was equal to that of the Romans in their best days, baffled his attempts, and a winter of extraordinary severity ensuing ruined the attack ing army. The importance of this result was incalculable to Europe far greater than that of the victory of Charles Martel at Tours, The Saracen empire was now at its height, and reached from the Indus to the Atlantic; and. it was the full brunt of this power, now in full tide of conquest, which was resisted at Constantinople. Had that city fallen, there was no power that could have prevented it from overrunning Europe. After this, Asia Minor con tinued for ages to be the battle-ground of the two opposing empires, until it was so devastated and depopulated by suc cessive campaigns as to be fit only for the occupation of the nomad tribes who were to succeed. In the midst of these struggles the invasions of Haroun al Rashid, the splendour of whose court obtained for him a reputation in the West which he did not enjoy among his contemporaries in the East, appear hardly more than plundering incursions. The Byzantine nobles, who were trained in this school of war, were distinguished for their military spirit and personal prowess ; and the troops of which the armies were composed were so powerful and well-disciplined that the Saracens would never meet them in the field except with far superior numbers. By sea, however, the empire was less successful than by land. During the first half of the 9th century both Crete and Sicily were conquered by these enemies, and in the year 904 occurred the memorable sack of Thessalonica. A Saracen fleet appeared before that city, and, after storm ing the sea-wall, pillaged the whole place and butchered the citizens without respect of sex or age. The most famous successes were those of Nicephorus Phocas and his successor John Zimisces. The former of these great commanders, who before he became emperor had reconquered the island of Crete, at the end of a brilliant campaign in Syria obtained possession of Antioch (968) after it had been in the hands of the Mahometans for 328 years. Five years later Zimisces carried his victorious arms even to the banks of the Tigris. But while the disorganized state of the caliphate of Baghdad, in the early part of the llth century, removed all fears from that quarter, a new enemy began to appear on the eastern frontier of the empire the Seljuk Turks. Unfortunately, at this critical conjuncture, a fatal mistake was made. The safety of that frontier had long been guaranteed by the Armenian kingdom of the Bagra- tians, whose country was admirably adapted for defence, and whose population were a hardy race of Christian mountaineers. In the year 1045 the emperor Constantino IX. destroyed this kingdom, and thereby laid his dominions open to the invaders.
In Europe, at the same time, the empire was exposed to the attacks of a foe hardly less formidable, and in closer proximity the Bulgarians. After the extinction of the Avars, this people, who had long been in subjection to them, had founded an important monarchy in the ancient Moesia at the end of the 7th century; and henceforward the Byzantines had to defend their European possessions, not as before against a succession of migratory tribes, but against the concentrated force of a single nation. In the time of Constantine Copronymus we find that it required all the energy and military talents of that emperor to keep them at bay, and on one occasion they carried their ravages up to the neighbourhood of the capital. In the beginning of the 9th century their king, Crumn, defeated and slew the emperor Nicephorus I., who had invaded his territory, in a night attack on his camp, and converted his skull into a drinking- cup for his table. We have already noticed how, later in that century, the nation embraced Christianity, and at the same time a tract of country on the southern side of the Balkan range was ceded to them, and received from them the name of Zagora. By this time also they had imperceptibly changed their nationality and their language, for by intermingling with the more numerous Slavonian tribes of the countries in which they settled, they lost the traces of their Hunnish origin, and became to all intents and pur poses a Slavonic race. By the neighbourhood of Constantinople, and the trade between that city and the German and Scandinavian peoples which passed through their country, they became a commercial nation, and advanced in the arts of life. But the rapacity of the Greeks in im posing heavy customs on their traders involved them again in war with the empire, and when peace was re-established, the treaty between Romanus I. and their king, Simeon, was made under the very walls of Constantinople (923). In the reign of Nicephorus Phocas the Russians, who had not long before appeared on the scene of action, were invited by the Greeks to invade Bulgaria, and they so effectually crushed the Bulgarians (968) that his successor, John Zimisces, was obliged to come to their aid, in order to save his own territory from falling a prey to the new comers. It was shortly after this that the great and final struggle commenced. Under their chief, Samuel, a man of great vigour and ability, they extended their conquests over Macedonia and Thessaly, and made plundering incursions into Greece and the Peloponnesus. But finding that the plains of Bulgaria were unfavourable to him as a seat of war, on account of the superior discipline of the imperial
