From 867 to the Ottoman conquest

Military revival

A reassertion of Byzantine military and naval power in the East began with victories over the Arabs by Michael III’s general Petronas in 856. From 863 the initiative lay with the Byzantines. The struggle with the Arabs, which had long been a struggle for survival, became a mounting offensive that reached its brilliant climax in the 10th century. By 867 a well-defined boundary existed between the Byzantine Empire and the territory of the ʿAbbāsid caliphate. Its weakest point was in the Taurus Mountains above Syria and Antioch. Basil I directed his operations against this point, recovered Cyprus for a while, and campaigned against the Paulicians, a Christian sect regarded as heretical by the Byzantines and whose anti-imperial propaganda was effective in Anatolia. But the conflict with Islam was one that concerned the whole empire, in the West as well as in the East, and by sea as well as by land. In 902 the Arabs completed the conquest of Sicily, but they were kept out of the Byzantine province of South Italy, for whose defense Basil I had even made some effort to cooperate with the Western emperor Louis II. The worst damage, however, was done by Arab pirates who had taken over the island of Crete. In 904 they plundered Thessalonica, carrying off quantities of loot and prisoners. Leo VI sent a naval expedition to Crete in 911, but the Muslims drove it off and humiliated the Byzantine navy off Chios in 912.

On the eastern frontier, the Byzantine offensive was sustained with great success during the reign of Romanus I Lecapenus by an Armenian general John Curcuas (Gurgen), who captured Melitene (934) and then Edessa (943), advancing across the Euphrates into the caliph’s territory. It was Curcuas who paved the way for the campaigns of the two soldier-emperors of the next generation. In 961 Nicephorus Phocas, then domestic (commander) of the armies in the West, reconquered Crete and destroyed the Arab fleet that had terrorized the Aegean for 150 years; he thereby restored Byzantine naval supremacy in the eastern Mediterranean. In 962 his strategy achieved unexpected triumphs all along the eastern frontier and culminated in the capture of Aleppo in Syria. When he was proclaimed emperor in March 963, Nicephorus appointed another Armenian general, John Tzimisces, as domestic of the East, though he retained personal command of operations against the Arabs. By 965 he had driven them out of Cyprus and was poised for the reconquest of Syria. The revived morale and confidence of Byzantium in the East showed itself in the crusading zeal of Nicephorus Phocas and John Tzimisces for the reconquest of Syria and the Holy Land. The ground lost to Islam in the 7th century was thus fast being regained; and, although Jerusalem was never reached, the important Christian city of Antioch, seat of one of the patriarchs, was recaptured in 969. These victories were achieved largely by the new cavalry force built up by Nicephorus Phocas. In the areas recovered from the Arabs, land was distributed in military holdings with the interests of the cavalry in mind. But the victories were achieved at the expense of the western provinces, and an attempt to recover Sicily ended in failure in 965.

The campaigns of John Tzimisces, who usurped the throne in 969, were directed against the Emir of Mosul on the Tigris and against the new Fāṭimid caliph of Egypt, who had designs on Syria. By 975 almost all of Syria and Palestine, from Caesarea to Antioch, as well as a large part of Mesopotamia far to the east of the Euphrates, was in Byzantine control. The way seemed open for Tzimisces to advance to the ʿAbbāsid capital of Baghdad on the one hand and to Jerusalem and Egypt on the other. But he died in 976 and his successor, Basil II, the legitimate heir of the Macedonian house, concentrated most of his resources on overcoming the Bulgars in Europe, though he did not abandon the idea of further reconquest in the East. The kingdom of Georgia (Iberia) was incorporated into the empire by treaty. Part of Armenia was annexed, with the rest of it to pass to Byzantium on the death of its king. Basil II personally led two punitive expeditions against the Fāṭimids in Syria, but otherwise his eastern policy was to hold and to consolidate what had already been gained. The gains can be measured by the number of new themes (provinces) created by the early 11th century in the area between Vaspurakan in the Caucasus and Antioch in Syria. The annexation of Armenia, the homeland of many of the great Byzantine emperors and soldiers, helped to solidify the eastern wall of the Byzantine Empire for nearly a century.

Relations with the Slavs and Bulgars

Although imperial territory in the East could be reclaimed only by military conquest, in the Balkans and in Greece the work of reclamation could be assisted by the diplomatic weapon of evangelization. The Slavs and the Bulgars could be brought within the Byzantine orbit by conversion to Christianity. The conversion of the Slavs was instigated by the patriarch Photius and carried out by the monks Cyril and Methodius from Thessalonica. Their invention of the Slavonic alphabet (Cyrillic and Glagolitic) made possible the translation of the Bible and the Greek liturgy and brought literacy as well as the Christian faith to the Slavic peoples. The work began in the Slavic kingdom of Moravia and spread to Serbia and Bulgaria. Latin missionaries resented what they considered to be Byzantine interference among the northern Slavs, and there were repeated clashes of interest that further damaged relations between the sees of Rome and Constantinople. The conversion of the Bulgars became a competition between the two churches and was ably exploited by the Bulgar king Boris until, in 870, he opted for Eastern Orthodox Christianity on condition of having an archbishop of his own.