The Heraclians (610-711)

The long reign of Justinian I (527-565) with his military conquests, which extended Byzantine frontiers, and his political and legal accomplishments, left a significant mark on the empire. Yet at the end of his reign and during those of his successors the situation of the empire was hardly flourishing. The late sixth century marked an important turning point: the empire was touched by a series of catastrophes and wars on all its fronts (with the Slavs, Bulgars, Persians and Avars). Although Maurice (582-602) won many important victories against the Persians, various invasions in addition to the internal crisis that followed Phocas' accession to power (602-610) destabilised the Empire.

In 608, Heraclius, founder of the Heraclian dynasty, set off from Carthage for Thessalonica. He arrived in Constantinople in 610 commanding a powerful fleet to overthrow Phocas. Phocas was arrested and immediately executed. The very same day, Heraclius married and was crowned emperor (610-641).

Heraclius inaugurated his reign in deliberate, sharp contrast to the despotism of Phocas and his failure to oppose the advances of the Persian Sasanians. In 614, the Persians took Jerusalem, making off with the Holy Cross and burning the Church of the Holy Sepulchre. Twice, in 617 and 619, the Slavs, under Avar command, laid siege to the city of Thessalonica, which put up resistance, and pushed farther with their attacks to Thessaly, the Peloponnese and even Crete in 623. Despite several truces signed with the Avars, Heraclius could not prevent them from besieging Constantinople in 626. Yet the walls, the powerful army of the capital and the energy of Patriarch Sergius, who placed icons of the Virgin at the gates, stopped the Avars' attempted conquest of Constantinople. After their defeat, the Avar threat was no longer a source of concern to the Byzantines. The Slavs, however, continued their expansion: by the end of the seventh century they had occupied most of the Balkans. Starting in 622, Heraclius launched a major offensive against the Sasanians, winning decisive victories thanks to a new tactic that used light horse-drawn chariots. Between 623 and 628, his army penetrated far into Persian territory; this uninterrupted military campaign signalled a resolutely offensive policy. His courage earned him the admiration of even his enemies. He scored a decisive victory against the Persian army in the Battle of Nineveh in 627, helped by the Khazars, a Turkic people from the north of the Caucasus. After his victory over Persia, Heraclius recovered the Holy Cross and personally bore it into the reconstructed Church of the Holy Sepulchre.

Heraclius' religious beliefs led him to undertake the first holy war; the territories he won back, however, were again lost to the Arabs in 636. After his death in 641, his son Constantine III Heraclius (641) succeeded him, but died in the same year, leaving the throne to his brother Heraclius II Heracleona, who had to abdicate in favour of his nephew Constans II Heraclius (641-668). Constans II succeeded in containing the Arab invasion and saving Constantinople. In 648, he promulgated an edit outlawing any Christological discussion in the interests of appeasing religious conflict. When a palace officer assassinated him in his bath, his son Constantine IV (668-685) ascended the throne, and it was he who finally put an end to the Arab invasion in the East. The Bulgars were by then becoming a significant threat to the Empire. Under the command of Asparukh, they reached the Danube delta around 670 and occupied the Dobruja region. Constantine IV, unable to attack them, negotiated a treaty recognising their borders and agreeing to pay them tribute. They soon developed an independent state whose capital was the town of Pliska.

Justinian II (685-695), the successor of Constantine IV, was determined to continue this policy towards the Arabs. He succeeded in obtaining a tribute from them, with joint possession of Cyprus, Armenia and Georgia. However, his defeat in 692 triggered a fresh period of instability, and the Arabs once again held the upper hand, recapturing Armenia and Cilicia. Justinian II returned to power (705-711), but could not prevent the loss of North Africa. Another siege of Constantinople seemed imminent, and the Arabs attacked the capital for a second time in 717. Leo III (717-741), who had just ascended the throne, succeeded in repelling the Arab land and naval forces. Caliph Omar II ordered a retreat.

Epidemics and wars on all fronts had a profound impact on the empire. There were considerable demographic consequences: the town populations were significantly reduced. Constantinople was severely affected and indeed few provinces were spared. The shrinking of the population caused the size of the towns to be reduced; for the most part, they were no more than kastra - refuges (kastron: "fortress" in Greek).

Diminished populations also weakened trade, and in fact the consequences of the wars were mainly economic. With excessive military spending, the Byzantines were overwhelmed by the cost of keeping their state functioning. It was only in the eighth century that the empire found the resources to regain some of their lost territories and become the major power in the Near East.

E. Y.