Byzantine Empire
10
and answered directly to the imperial administration. This system may have had its roots in certain ad hoc measures taken by Heraclius, but over the course of the seventh century it developed into an entirely new system of imperial governance.
The withdrawal of large numbers of troops from the Balkans to combat the Persians and then the Arabs in the east opened the door for the gradual southward expansion of Slavic peoples into the peninsula, and, as in Anatolia, many cities shrank to small fortified settlements. In the 670s, the Bulgars were pushed south of the Danube by the arrival of the Khazars, and in 680 Byzantine forces which had been sent to disperse these new settlements were defeated. In the next year Constantine IV signed a treaty with the Bulgar khan Asparukh, and the new Bulgarian state assumed sovereignty over a
number of Slavic tribes which had previously, at least in name, recognized Byzantine rule. In 687–688, the emperor Justinian II led an expedition against the Slavs and Bulgars which made significant gains, although the fact that he had to fight his way from Thrace to Macedonia demonstrates the degree to which Byzantine power in the north Balkans had declined.
The final Heraclian emperor, Justinian II, attempted to break the power of the urban aristocracy through severe taxation and the appointment of "outsiders" to administrative posts. He was driven from power in 695, and took shelter first with the Khazars and then with the Bulgars. In 705 he returned to Constantinople with the armies of the Bulgar khan Tervel, retook the throne, and instituted a reign of terror against his enemies. With his final overthrow in 711, supported once more by the urban aristocracy, the Heraclian dynasty came to an end.
Leo III the Isaurian, turned back the Muslim assault in 718, and achieved victory with the major help of the Bulgarian khan Tervel, who killed 32,000 Arabs with his army. He also addressed himself to the task of reorganizing and consolidating the themes in Asia Minor. His successor, Constantine V, won noteworthy victories in northern Syria, and thoroughly undermined Bulgar strength.
In 826, the Arabs captured Crete, and successfully attacked Sicily, but on 3 September 863, general Petronas gained a huge victory against Umar al-Aqta, the emir of Melitene. Under the leadership of Krum the Bulgar threat also reemerged, but in 814 Krum's son, Omortag, arranged a peace with the Byzantine Empire.
The military successes of the tenth century were coupled with a major cultural revival, the so-called Macedonian Renaissance. Miniature from the Paris Psalter, an example of Hellenistic-influenced art.