Emperor Heraclius (ca. 575–641) came to power in 610 after instigating an overthrow of the reputedly tyrannical Emperor Phokas. Entering Constantinople, so the story goes, Heraclius captured Phocas and demanded: "Is this how you have ruled, wretch?" The belittled emperor replied, "And will you rule better?"
Heraclius proved his strength, if not his wit, by first removing Phocas's head, and then his genitalia. The first years of Heraclius's reign were characterized by a number of military campaigns against the Persians, who were threatening the eastern frontier of the empire, and the Slavs and Avars, who were invading the northern Balkans. A crucial turning point occurred in 626 when the Persian commander Shahrbaraz and the Avars unsuccessfully attacked Constantinople. Their retreat allowed Heraclius to take the offensive position, invade Persia, and extract a peace treaty. By 629 Heraclius had regained Egypt from Persian rule.
Although his military success was temporary—in 634 the Arabs invaded Syria and destroyed the Byzantines at Yarmuk—Heraclius's victories in Persia, where he recovered the True Cross, were remarkable. The splendid David Plates might have been created in his honor. The emphasis on David's valor evoked Heraclius's military successes. By representing the legitimacy of David's claim to succeed Saul, the plates also cast Heraclius as the "new David," supporting the authenticity of his position as emperor (even though he did not take the seat of authority in the most decorous way).
In addition to military campaigns, Heraclius also battled in the religious sphere, hoping to resolve the church's split over beliefs about the nature of Christ. With Sergios I, the patriarch of Constantinople (r. 610–38), and Kyros, the Chalcedonian archbishop of Alexandria (r. 631–42), Heraclius promoted Monoenergism—a view that defined the two natures of Christ operating through a single energy. This compromise position was not accepted, nor was the alternative position, Monotheletism—a view in which the two natures of Christ are united in a single will. The religious debates were not quelled under Heraclius, and they continued to divide believers into the reign of succeeding rulers.
Despite his inability to establish full religious or political unity, Heraclius was crucial to the character of the Byzantine empire. The wide geographical range represented by the coins from his reign demonstrate that he oversaw a level of prosperity throughout the empire. Meanwhile, the institution of Greek (instead of Latin) as the official language of the state indicates his central role in participating in, if not facilitating, massive cultural change.
 Olster 1991, 133; Charles 2007, 177. Alexander, 236; Evans, "Plates with Scenes from the Life of David," 17.
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