Byzantine emperor. Leo III, whose original name was Konon, is popularly known as Leo the Isaurian. He was born possibly in 680 in Germanikeia, a city in the ancient country of Commagene in the Roman province of Syria (present-day Maras in southeastern Turkey). It is not clear when, but he entered the service of Byzantine emperor Justinian II (r. 685-695) and was sent by him on a diplomatic mission and then was appointed general (strategus) by Emperor Anastasius II (r. 713- 715). When Anastasius was deposed, Leo joined with another general, Artabasdus, to overthrow the usurper and the new emperor Theodosius III (r. 715-717), who had done little to prepare the empire for an impending Muslim assault on Constantinople. Leo entered Constantinople on March 25, 717; forced the abdication of Theodosius; and assumed the throne, taking the name of Leo III.
As emperor, Leo immediately set to work preparing Constantinople for attack, strengthening its defenses and laying in stocks of food to meet a large Muslim force sent by Caliph Suleiman ibn Abd al-Malik and commanded by his general Maslamah. The Muslims hoped to take advantage of the chaos in the Byzantine Empire to capture the great city of Constantinople. the Muslim army besieged the walls of the capital, and Suleiman’s 1800 ships sailed into the Marmara. Leo gained Bulgarian help in this crucial war to stop the Muslim expansion from entering eastern Europe. Once again Greek fire enabled the Byzantine navy to destroy the Muslim fleet, though the blockade lasted a year until August 718. That year Sicily general Sergius tried to proclaim a new Emperor, and two years later ex-Emperor Anastasius II escaped from Thessalonica and tried to reclaim power with Bulgarian support; but both these efforts failed. Muslim armies invaded Asia Minor every year from 726 to 740, when they were defeated by Leo’s army at Acroinon. Leo’s son Constantine married a daughter of the Khazar Khan in 733. Having become Emperor after being the military governor of a powerful theme, Leo divided the larger themes into two parts. Western Anatolia became the Thracesion theme. The maritime Carabisian theme was divided, though the large Opsikion theme was still governed by Leo’s son-in-law Artabasdus.
Having preserved his empire from Muslim overlordship, Leo turned his attention to administrative reform. In 718 he suppressed a rebellion in Sicily, and the next year he crushed an attempt to restore deposed emperor Anastasius II. Leo also reorganized the army and helped restore depopulated areas of the empire by inviting Slavic settlers to live there. He also formed alliances with the Khazars and the Georgians. His reforms were so successful that when the Muslims again invaded the empire in both 726 and 739, they were decisively defeated.
Leo also introduced important legal reforms in the empire that changed taxes and raised the status of serfs to free tenants. He rewrote the law codes, and in 726 he published a collection of his legal reforms, the Eclogia.
Leo’s most striking reforms were probably in the area of religion, where he insisted on the baptism of all Jews and Montanists in the empire in 722 and then embarked on iconoclasm, issuing a series of edicts that prohibited the worship of images. Although many people supported his iconoclasm, a number of others, especially in the western part of the empire, did not. In 727 the imperial fleet crushed a revolt in Greece that had been prompted chiefly by religious reasons. Leo replaced the patriarch of Constantinople, who disagreed with him in the matter of icons. Leo also clashed with Pope Gregory II and Pope Gregory III in Italy on this issue. In 727 Leo sent a large fleet to Italy to crush a revolt in Ravenna, but a great storm largely destroyed the fleet, and southern Italy successfully defied him, with the exarchate of Ravenna in effect becoming free of Byzantine control. Leo continued as emperor until his death on June 18, 741. He was succeeded by his son, Constantine V.
A resourceful, energetic, and bold general, Leo saved the Byzantine Empire and, not incidentally, Western civilization from Muslim control. He also won time for the Byzantine Empire to recover from its early political chaos and survive.
The Second Siege of Constantinople and the Fall of the Umayyad Dynasty (717–50)
The continuing turmoil in Constantinople could not have gone unnoticed in Damascus. Earlier that same year Sulayman ibn Abd al-Malik assumed the caliphate and inaugurated his rule by propelling his brother, Maslamah ibn Abd al-Malik, into Asia Minor at the head of 80,000 troops, while a huge armada of reportedly 1,800 vessels made its way around the south coast. Constantinople was about to experience its most dire confrontation with Islam until its final fall over seven centuries later.
The details of the ensuing epic engagement are discussed in a separate section at the end of the chapter as an example of sea combat in the period, but it suffices to say here that it unfolded in a manner similar to the siege of 672–8, with much the same result. As the Arab forces approached Constantinople in the spring of 717, Leo the Isaurian, the strategos of the Anatolikon Theme, engineered a coup to replace the ill-suited Theodosios III on the throne. Under his inspired leadership as Leo III, the Byzantines then used dromōns spewing ‘Greek fire’ to break up an Umayyad attempt to blockade the Bosporus. The besieging Arab army fared even worse. A particularly harsh winter ravaged it with deprivation and disease. And the following spring offered little relief. Nearly 800 supply ships arrived from Egypt and Ifriqiyah, but their Coptic Christian crews switched sides en masse. Without the precious provisions which these ships carried, Maslama’s troops fell easy prey to the Bulgars of Khan Tervel, with whom Leo had formed a propitious alliance. The Bulgars butchered some 22,000 of the Arabs. Umar ibn Abd al-Aziz, the new caliph, had little choice but to recall his forces. It was a battered Umayyad army that retreated across Asia Minor in the autumn of 718 and only five vessels of the once massive Muslim armada managed to run the gauntlet of autumn storms in the Hellespont and Aegean to reach their home port.
It was a disastrous Muslim defeat, which should have put Islam on the defensive for decades to come, but inexplicably Leo chose this time to delve into the religious controversy that was to be the bane of Byzantium. In 726 he inaugurated Iconoclasm (literally, ‘the smashing of icons’) by ordering the removal of the icon of Christ over the Chalke entrance to the imperial palace in Constantinople. In 730 he followed up this action with an imperial decree against all icons. This polemical policy was to rend the fabric of the empire for the next fifty-seven years. It proved particularly unpopular in Italy and the Aegean areas. In early 727 the fleets of the Hellas and Karabisian Themes revolted and proclaimed a certain Kosmas as emperor. Leo managed to devastate and disperse these fleets with his own, again using ‘Greek fire’, the secret of which was apparently restricted to Constantinople at the time.
The episode, nonetheless, prompted the emperor to dissolve the troublesome Karabisian Theme and restructure the provincial fleets in order to dilute their threat to the throne. Leo placed the south coast of Asia Minor, formerly a responsibility of the disbanded Karabisian Theme, under the authority of the more tractable droungarios of the Kibyrrhaeot fleet, whose headquarters was transferred to Attaleia (present-day Antalya). Land-based themes, like the Hellas and Peloponnesos, were also allowed to maintain fleets of their own. These modifications to fleet organization were probably intended to help defuse naval power and make it more subservient to the emperor.
Despite their humiliating failure before the walls of Constantinople, the Umayyads took advantage of continued Byzantine upheaval both in the palace and in the Church to nibble away at the edges of the empire. A long period of raid and counter-raid ensued between Damascus and Constantinople, mostly involving either Egypt or Cyprus. But ultimately the Byzantines’ advantage in naval organization, possession of ‘Greek fire’ and virtual monopoly of such critical shipbuilding materials as wood and iron ensured they would prevail, at least in the eastern Mediterranean. The climax of the contest came in 747, when the Kibyrrhaeot fleet surprised an enormous armada from Alexandria in a harbour on Cyprus called Keramaia (exact location unknown). ‘Out of 1,000 dromōns it is said only three escaped,’ professed Theophanes. This was undoubtedly a chauvinistic exaggeration, but Umayyad naval power was evidently broken by the outcome of the battle and never again posed a serious threat to the Byzantine Empire. The Umayyad Dynasty came to an end just three years later when the Abbasids led by Abu al-Abbas as-Saffah crushed Caliph Marwan II at the Battle of Zab (Mesopotamia) in late January 750. The subsequent Abbasid Caliphate moved its capital from Damascus to Baghdad and focused its initial attention on the East.
Further Reading Bury, J. B. A History of the Later Roman Empire from Arcadius to Irene. 2 vols. Amsterdam: Hakkert, 1966. Gero, Stephen. Byzantine Iconoclasm during the Reign of Leo III, with Particular Attention to the Oriental Sources. Louvain: Secrétariat du Corpus SCO, 1973. Guilland, Rodolphe. “L’expédition de Maslama contre Constantinople (717-718).” In Études Byzantines, 109-133. Paris: Presses universitaires de France, 1959. Ladner, Gerhart. “Origin and Significance of the Byzantine Iconoclastic Controversy.” Mediaeval Studies 2 (1940): 127-149. Ostragorsky, George. A History of the Byzantine State. Translated by John Hussey. New Brunswick, NJ: Rutgers University Press, 1969. Treadgold, Warren. A History of the Byzantine State and Society. Stanford, CA: University of Stanford Press, 1997.