The Byzantine Empire was ruled by emperors of the Heraclian dynasty from 610 to 711 AD. The Heraclian period encompassed the Byzantine–Sasanian War of 602–628, the Early Muslim conquests, and major political, military, religious, and administrative changes that transformed the Roman Empire in the eastern Mediterranean. The reign of Heraclius began during a period of severe crisis, when the Empire was at war with the Sasanian Empire and faced political instability and military pressure on several fronts. Heraclius is generally considered to have probably been of Armenian descent, although the origins of his family remain debated and some sources associate his family with Cappadocia. At the beginning of the dynasty, the Empire retained much of the political, institutional, and cultural heritage of the Roman state of Late Antiquity. During the seventh century, however, prolonged warfare, territorial losses, economic disruption, demographic changes, and internal religious controversies contributed to a profound transformation of the Empire.
By the end of the Heraclian period, the Empire had lost most of its territories outside Asia Minor, the Balkans, and a number of remaining possessions in the Mediterranean. Its political and military institutions had adapted to the conditions of the seventh century, while Greek had increasingly replaced Latin as the dominant language of administration and public life. The Empire was increasingly characterized by a more compact territorial core and a society shaped by prolonged warfare with the Caliphate. These developments contributed to the emergence of the medieval Byzantine state, although its rulers and inhabitants continued to identify themselves as Romans. The period ended with the second deposition of Justinian II in 711 and was followed by the period of political instability known as the Twenty Years' Anarchy.
The Heraclian dynasty was named after the emperor Heraclius, who, together with his father Heraclius the Elder, the Exarch of Africa, led a revolt against the emperor Phocas in 608. In 610, Heraclius sailed from Carthage to Constantinople, overthrew Phocas, and became emperor. At the time of his accession, the Empire was engaged in the Byzantine–Sasanian War of 602–628. The Sasanian armies subsequently captured large parts of the Empire's eastern territories, as well as Egypt and parts of Anatolia. After a series of military campaigns, Heraclius defeated the Sasanian forces and brought the war to an end in 628. The Empire temporarily recovered its eastern territories, but these gains were soon threatened by the rapid expansion of the Early Muslim conquests from the Arabian Peninsula.
Heraclius's successors struggled to contain the expanding Muslim caliphates. The Levant, Egypt, and much of North Africa were lost during the seventh century, while an Arab army and fleet attacked Constantinople during the Siege of Constantinople (674–678). Nevertheless, the Empire survived and gradually adapted to its reduced territory. The development of the theme system helped organize the military and administrative resources of the imperial heartland, particularly in Asia Minor, although the chronology and nature of the system's early development remain debated among historians. Under Constans II and Constantine IV, the Empire continued to resist Arab expansion while also confronting threats in the Balkans. Under Justinian II, Byzantine military activity in the East continued, while the Empire also became increasingly involved in conflicts with the Bulgars.
The latter part of the seventh century also saw the emergence of a major new power in the Balkans. In 680–681, the Byzantines were defeated by the Bulgars under Asparukh, and the First Bulgarian Empire was established south of the Danube. The Byzantine Empire subsequently recognized the Bulgarian state, which became an important political and military power in the Balkans. The Heraclian period ended in 711, when Justinian II was overthrown and killed during a revolt led by Philippikos Bardanes. His death brought the Heraclian dynasty to an end and ushered in a period of political instability known as the Twenty Years' Anarchy.
Background
Ever since the fall of the Western Roman Empire, the Eastern Roman Empire continued to see Western Europe as rightfully Imperial territory. However, only Justinian I attempted to enforce this claim with military might. Temporary success in the West was achieved at the cost of Persian dominance in the East, where the Byzantines were forced to pay tribute to avert war.
However, after Justinian's death, much of newly recovered Italy fell to the Lombards by 610, and the Visigoths soon reduced the imperial holdings in Spain by 624-625. At the same time, wars with the Persian Empire brought no conclusive victory. In 591 however, the long war was ended with a treaty favorable to Byzantium, which gained Armenia. Thus, after the death of Tiberius II, Maurice sought to restore the prestige of the Empire.
Even though the Empire had gained smaller successes over the Slavs and Avars in pitched battles across the Danube, both enthusiasm for the army and faith in the government had lessened considerably. Unrest had reared its head in Byzantine cities as social and religious differences manifested themselves into Blue and Green factions that fought each other in the streets. The final blow to the government was a decision to cut the pay of its army in response to financial strains. The combined effect of an army revolt led by a junior officer named Phocas and major uprisings by the Greens and Blues forced Maurice to abdicate. The Senate approved Phocas as the new Emperor and Maurice, the last emperor of the Justinian dynasty, was murdered along with his four sons.
The Persian King Khosrau II responded by launching an assault on the Empire, ostensibly to avenge Maurice, who had earlier helped him to regain his throne. Phocas was already alienating his supporters with his repressive rule (introducing torture on a large scale), and the Persians were able to capture Syria and Mesopotamia by 607. By 608, the Persians were camped outside Chalcedon, within sight of the imperial capital of Constantinople, while Anatolia was ravaged by Persian raids. Making matters worse was the advance of the Avars and Slavic tribes heading south across the Danube and into Imperial territory.
While the Persians were making headway in their conquest of the eastern provinces, Phocas chose to divide his subjects rather than unite them against the threat of the Persians. Perhaps seeing his defeats as divine retribution, Phocas initiated a savage and bloody campaign to forcibly convert the Jews to Christianity. Persecutions and alienation of the Jews, a frontline people in the war against the Persians helped drive them into aiding the Persian conquerors. As Jews and Christians began tearing each other apart, some fled the butchery into Persian territory. Meanwhile, it appears that the disasters befalling the Empire led the Emperor into a state of paranoia—although it must be said that there were numerous plots against his rule and execution followed execution. Among those individuals who were executed was the former empress Constantina and her three daughters.
Heraclius
Fall of Phocas
Due to the overwhelming crisis facing the Empire that had pitched it into chaos, Heraclius the Elder now attempted to seize power from Phocas in an effort to restore stability. As the Empire was led into anarchy, the Exarchate of Africa remained relatively out of reach of Persian conquest. Far from the incompetent Imperial authority of the time, Heraclius, the Exarch of Carthage, with his brother Gregoras, began building up his forces to assault Constantinople. After cutting off the grain supply to the capital from his territory, Heraclius led a substantial army and a fleet in 608 to restore order in the Empire. Heraclius gave the command of the army to Gregoras' son, Nicetas, whilst command of the fleet went to Heraclius' son, Heraclius the Younger. Nicetas took part of the fleet and his forces to Egypt, seizing Alexandria towards the end of 608. Meanwhile, Heraclius the Younger headed to Thessalonica, from where, after receiving more supplies and troops, he sailed for Constantinople. He reached his destination on 3 October 610, where he was unopposed as he landed off the shores of Constantinople, citizens greeting him as their deliverer.
When Phocas was delivered to Heraclius, an interesting conversation took place:
The reign of Phocas officially ended in his execution and the crowning of Heraclius by the Patriarch of Constantinople two days later on 5 October. A statue of Phocas that rested in the Hippodrome was pulled down and set aflame, along with the colors of the Blues that supported Phocas.
Early failures After having married his wife in an elaborate ceremony and crowned by the Patriarch, the 36-year-old Heraclius set out to perform his work as Emperor. The early portion of his reign yielded results reminiscent of Phocas' reign with respect to trouble in the Balkans. The Avars and Slavs poured through the western Adriatic, as well as through the southern and eastern portions of the Aegean area. Their large forces and strategic movement into Dalmatia engulfed several Byzantine cities, namely Singidunum (Belgrade), Viminacium (Kostolac), Naissus (Niš), Sardica (Sofia), and destroyed Salona in 614. However, numerous attempts to take the city of Thessalonica by the Slavs and Avars ended in failure, allowing the Empire to hold onto a vital city in the region.
In 613, the Byzantine army suffered a defeat at Antioch, allowing the Persians to move freely and effectively in all directions. This rapid advance caused the cities of Damascus and Tarsus to fall, along with Armenia. More seriously, however, was the loss of Jerusalem, which was besieged and captured by the Persians in three weeks. Countless churches in the city (including the Holy Sepulchre) were burnt and numerous relics, including the True Cross, the Holy Lance and the Holy Sponge, present at the time of Jesus Christ's death, were now in Ctesiphon, the Persian capital. The Persians remained poised outside of Chalcedon, not too far from the capital, and the province of Syria was in total chaos.
Despite Nicetas' earlier efforts, Egypt was also conquered, resulting in a significant loss in manpower, food supplies and revenue. However, the situation was not entirely hopeless. Constantinople's walls were as powerful and well-defended as ever, and Heraclius still had a large, better-trained, and better-armed fleet than any of his "barbarian" opponents (especially the Slavs and Avars). The Persians had no vessels in the Bosporus, and thus unable to effectively besiege the city.
Byzantine counter offensive