LEO III, EMPEROR OF THE EAST, called the ISAURIAN. — His accession to the throne took place on 25 March 717, on the eve of a great effort by the caliphate of Damascus to seize Constantinople. The Christian capital was in fact besieged by large Arab forces on land and sea from August 717 to August 718.
L. had been strategos of the third Anatolikon: a native of Isauria or of Germanicia in Syria, he knew well the customs and the art of warfare of the Arabs. He succeeded in forcing the besiegers to withdraw after they had suffered heavy losses: from this moment began the halt of the Arab offensive against the Byzantine Empire. Fighting nevertheless continued in eastern Anatolia: the battle of Akroinon in 739 represented a further retreat of the Islamic threat. For greater security, L. III had succeeded in establishing good relations with the khan of the Bulgars.
Nor was L. III’s government peaceful internally: a rebellion by the strategos of Sicily, Sergius, and an attempt by the former basileus Anastasius II disturbed II. In 720, however, L. III had already had his son Constantine V (born in 718) crowned and proclaimed his colleague, thereby initiating a new dynasty and pacifying the Empire.
The struggle against the veneration of images initiated by L. III has obscured his figure in historiographical tradition and veiled his qualities as a statesman and reorganizer, as well as his qualities as a warrior. The importance of his work has been much debated in recent scholarship. He was customarily regarded as the author of various legislative acts: the military law, the maritime law, and the rural code, which were thought to have prepared the publication of the great code called the Eelaga, issued in 740. The iconoclastic measures were supposedly connected with this complex legislative activity. This picture has been challenged by modern criticism, which attributes the maritime law to the period 600–800, without the possibility of greater precision, and the rural code to the age of Justinian II. Certainly the Eelaga is L. III’s, and in its preface he declared the purpose of the legislative reform: to make the law more precise and clearer, and to ensure a better administration of justice. It is certainly more inspired than Justinian’s Code by Christian humanitarian conceptions, especially with regard to the family.
What, on the other hand, was the purpose of the prohibition of the veneration of sacred images remains even today a matter of debate. Research is made difficult by the destruction of the iconoclasts’ polemical writings, imposed by the councils that reaffirmed iconoduly in the ninth century. Some critics, such as Paparrigopulo, saw in L. III a kind of despotic, enlightened monarch who had a program of defending secular power, struggling against religious interference in the State, or opposing the encroachment of the monastic element. Others believe that L. III and his successors and partisans were moved by religious concerns, by the purpose of purifying the Church and combating the incipient idolatry that they saw emerging behind the lively veneration rendered to the images of the saints. But it cannot be excluded that L. III, following the old Constantinian and Justinian traditions, was concerned to assert the authority of the imperial government over the Church, shaken by the grave crisis of the seventh century. The iconoclastic conception of Judaism and Islam must not be forgotten: the chronicler Theophanes attributes sympathy for these currents to L. III. The heresy of the Paulicians was also iconoclastic, and Anatolia was already dominated by this movement of ideas, so that L. III’s decisions must be judged not as the impulsive and capricious outburst of fanaticism, but as the expression of a spiritual movement that prevailed among part of the Empire’s population. Certainly, however,
L. III and his son and successor Constantine V did not sufficiently assess the religious and social forces that would oppose them. V. ICONOCLASTIA.
The chronology of the iconoclastic reform is not entirely certain. The first measures seem to date from 726. Was an explicit decree already issued, or were there merely attempts to induce the Church to consent to the project? Certainly, in 727 riots had already broken out in Constantinople over the removal of Christ of Chalkoprateia; riots also occurred in Greece and the Cyclades, where a counter-emperor was proclaimed. Lively opposition movements also arose in the Byzantine provinces of Italy. Pope Gregory II adopted a protesting stance, as demonstrated by his letters to L. III, letters now considered authentic and regarded as having been written between 727 and 729. The Emperor reacted energetically, suppressing every attempt at rebellion and protest: in Italy, the attempt of the counter-emperor Tiberius Petasius failed. In his protest, the Pope in fact did not go beyond the limits of the strictest loyalism, restraining the greed of the Lombard king Liutprand, eager to lay hands on the Byzantine provinces, and at the same time calming the populations ready to rebel.
L. III was nevertheless determined to proceed. On 17 January 730 he proclaimed a solemn edict against the iconoclastic cult and deposed the patriarch Germanus, who opposed II. The new Pope Gregory III adopted a more energetic attitude than his predecessor and at the Roman Council of 731 excommunicated the iconoclasts. The Emperor responded by confiscating the patrimonies of the Roman Church located in the imperial territories and placing the Byzantine provinces of Italy under the patriarchate of Constantinople. Thus the Church was once again afflicted by a heresy and a schism.