Coin bearing the image of Emperor Leo III "The Isaurian"
Justinian II’s reign ended in anarchy, which lasted through the next six years, during which two additional Emperors briefly held power. Order was restored when Leo III seized power in 717. Leo was an able general and civil ruler who sought to reform the administrative and military structure of the Empire. As a pious Christian, however, he desired ecclesiastical and theological reform. In the preface to his law code the Ecloga, he affirmed that since God had given him the office of Emperor, it was his right and responsibility to care for the Church. For Leo, Runciman writes,
It is the Patriarch’s business to see to the spiritual well-being of the Empire. But it is the Emperor alone who can give to the recommendations of the Patriarch the force of law. His is the ultimate decision on religious as well as civil affairs. He is still the Viceroy of God.Leo’s firm conviction of his right to govern the Church led him to institute religious reform. The most significant change he introduced was state support for iconoclasm, the destroying of religious images. Leo initiated his campaign of iconoclasm by making public speeches and sermons against the veneration of icons. He then removed the long-standing icon of Christ that hung over the Palace gate, prompting a riot among the people of Constantinople. Leo severely punished the rioters. When the Patriarch Germanus protested, Leo removed him from office. When the Pope protested, excommunicating all those who destroyed icons, Leo transferred the province of Illyria from the jurisdiction of Rome to that of Constantinople. Leo justified his actions to the Pope by calling himself Pontifex, or priest-king.
Leo’s son Constantine V carried Leo’s policies to a more extreme level. He initiated a persecution of iconodules (icon venerators) that was far more severe than any persecution that his father had carried out. He especially targeted monastics, whom he saw as a hotbed of icon veneration and even rebellion against Imperial policy. Unlike his father, he saw limitations on his own authority over the Church; as a result, he sought ecclesiastical sanction for iconoclasm. In 754, he summoned a council that, under pressure from the Emperor, denounced iconoclasm as a heresy and set forth strict ecclesiastical and legal penalties for anyone caught making or venerating an icon. Leo and Constantine’s iconoclastic policies were continued, albeit in a more moderate form, by their immediate successor. But they were not accepted by the overwhelming majority of the Byzantine people. This demonstrated the limitations of the powers of the Viceroy of God; as Runciman states, “even the Holy Emperor, the Priest-King, as he claimed to be, could not permanently force upon his people a theology that the people disliked.”