Having thus saved the Empire from extinction, Leo proceeded to consolidate its administration, which in the previous years of anarchy had become completely disorganized. In 718 he suppressed a rebellion in
Sicily. The following year saw the deposed Emperor
Anastasius II raise an army and attempt to retake the throne, but he was captured and executed by Leo's government. The rebellion was the only serious threat to Leo's usurpation. Umayyad attacks under Caliph
Hisham ibn Abd al-Malik continued in the form of yearly raids in eastern and central
Asia Minor (see hatched area in figure), which affected communications, commerce and agricultural production. In 721, the city of
Dalisandus was captured, followed by the fortresses of
Kamachon and
Ikonion in 723/724 and several frontier fortresses in 725.
Caesarea (Cappadocia) was captured in 727, then
Gangra in 728. The Byzantine counter-raids were generally of little strategic impact, although crucially a major invading force was destroyed in the
Battle of Akroinon of 740. It was only during the
Third Fitna of 744–747, a civil war within the Umayyad Caliphate, that the regularity of attacks were temporarily interrupted. Leo secured the Empire's frontiers by inviting
Slavic settlers into the depopulated districts and by restoring the
army to efficiency. Leo effected many political and ecclesiastical restructurings in order to bolster the authority of the Empire and the
Patriarch of Constantinople. Since the end of the seventh century, imperial
stratēgoi were sent to the theme of Sicily (which included
Calabria), and in 732–733 Leo deprived the church of Rome of the
patrimony of St Peter in the theme, reallocating tax income that originally went to the church of Rome to the imperial administration (a large annual sum of 350 pounds of gold). However in 743, Constantine V compensated
Pope Zachary for this loss by granting him the estates of Ninfa and Norma to the south of Rome. Between 732 and 754, the bishops of Illyricum,
Crete, Sicily, Calabria and
Naples (until 769) were transferred from the authority of Rome to Constantinople. The Isaurians in general saw the church and its patriarchs as subordinate to the imperial will. The
740 Constantinople earthquake damaged the
Walls of Constantinople, the restoration of which Leo paid for out of the imperial treasury, raising the City taxes by 81⁄3 per cent in order to do so, as was recorded on the land walls near the
Sea of Marmara. The Empire of the eighth century was characterized by ruralization and depopulation, which along with the Arab invasions motivated Leo to undertake intense centralization and militarization, particularly involving the many fortresses and walls in towns such as
Nicaea and
Padyandus. Leo III died of
dropsy on 18 June 741 and was buried in the
Church of the Holy Apostles.
Iconoclastic policies cross in the
apse of the
Hagia Sophia, Thessaloniki. This mosaic is exemplary of the 8th-century iconoclast style, in which prominence to the symbol of the cross was given rather than to icons. Leo's most striking legislative reforms dealt with religious matters, especially
iconoclasm ("icon-breaking," therefore an iconoclast is an "icon-breaker"). After an apparently successful attempt to enforce the
baptism of all
Jews and
Montanists in the empire (722), he issued a
series of edicts against the veneration of images (726–729). A revolt broke out in Greece under the leadership of
Agallianos Kontoskeles, mainly on religious grounds, with a certain Kosmas being declared rival emperor. The imperial fleet quashed the uprising in 727 by way of
Greek fire. In 730, Patriarch
Germanus opted to resign rather than subscribe to iconoclasm; Leo replaced him with
Anastasius, who willingly sided with the Emperor on the question of icons. Patriarch
John V of Jerusalem along with
John of Damascus fiercely opposed imperial iconoclasm, issuing a pamphlet entitled
Adversus Constantinum Caballinum. A later polemical version of the pamphlet attributes to Leo the saying, "I am emperor and priest." In the
Italian Peninsula, the defiant attitude of Popes
Gregory II and later
Gregory III on behalf of image-veneration led to a fierce quarrel with the Emperor, with the
Liber Pontificalis stating that Gregory II "took up arms against the emperor as if against an enemy." In Rome, the population was more sympathetic to iconodulia, killing a pro-imperial duke and blinding another, while in Naples, iconoclasm was broadly well-received. A conflict between pro- and anti-imperial factions in the
Exarchate of Ravenna led to the death of
Exarch Paul. The struggle was accompanied by an armed outbreak in the Exarchate in 727, which Leo endeavoured to subdue by means of a large fleet. The new Exarch,
Eutychius, disembarked in Naples but could not enter Rome and assert his authority. This led to an unexpected alliance between Liutprand and Eutychius against Gregory, who, however, managed to convince the King, appealing to his piety, to return north and the Exarch to put down a revolt in
Etruria led by the usurper
Tiberius Petasius.
Analysis of Leo's iconoclasm Scholars offer various explanations for the ban on venerating icons . On the basis of Patriarch Germanus' letters read at the 787
Second Council of Nicaea, which state that the bishops Constantine of
Nakoleia and Thomas of
Claudiopolis had forbidden the veneration of icons even before 730, some scholars argue that the alleged
aniconism of the eastern part of the Empire, Leo's place of origin, motivated his policies. The phrase "I am emperor and priest" attributed to Leo by later iconodule polemicists represents the characteristically Isaurian imperial ascendancy over the church, which was rejected in the mid-9th century after Patriarch
Methodios I of Constantinople purged the clergy of iconoclasts, asserting the autonomy of the church against the iconoclast emperor,
Theophilos (). Others have discussed the mutual influence of Muslim and Byzantine iconoclasm, noting that
Caliph Yazid II had issued an iconoclastic edict, also targeting his Christian subjects, already in 721. According to historian Marie-France Auzépy, these explanations are insufficient. She appeals to an explanation by Byzantine chroniclers, that a terrifying volcanic eruption at
Thira in 726 was interpreted by Leo as a manifestation of God's wrath. In the
Bible, God allows his people to fall to
Babylonian captivity because of their
idolatry. Thus, Auzépy says, the banning of the veneration of images was fundamentally a rejection of idolatry in order to ensure the survival of the Christian people of the Empire, a decision which was apparently vindicated by the abatement of the Arab and Bulgar threat during Leo's reign. Some scholars, such as Leslie Brubaker and John Haldon, doubt whether there was any active imperial involvement in iconoclasm at all, proposing instead that Leo made a qualified critique of the use of images in public spaces, likely leading to the adoption of a somewhat iconoclastic attitude among the clergy in the late 730s or early 740s. The notion that there was mass imperial persecution and destruction of images is dismissed as a later "iconophile myth". Brubaker and Haldon support this hypothesis by pointing to the absence of any reports of iconoclasm in several contemporary accounts, including those of
Willibald, who travelled to Nicaea from 727 to 729, Germanus and even
John of Damascus. The
Venerable Bede does refer to a critique of images in Constantinople, and Germanus and John of Damascus say that the clergy was divided on the issue of iconoclasm, however there was no evidence of widespread support for the iconoclastic policies or of systematic removal of images under Leo. Brubaker and Haldon attribute a more moderate iconoclasm to Leo, "It is quite possible that Leo did attempt to restrict the public display of certain types of image and to remove them from certain places in churches (near the
altar and in the
apse, for example) to avoid their receiving the honour due to God alone", confirming this conclusion with the writings of Germanus and John of Damascus which appear to describe a kind of initial or moderate stage of iconoclasm.
Legislation Leo reformed the
silention, a type of restricted council instituted by
Justinian I, transforming it into a special assembly in the
Great Palace of Constantinople, in which the emperor would announce a solemn decision. Leo undertook a set of civil reforms including the abolition of the system of prepaying taxes which had weighed heavily upon the wealthier proprietors, the elevation of the
serfs into a
class of free
tenants and the remodelling of
family law,
maritime law and
criminal law, notably substituting
mutilation for the
death penalty in many cases. These punishments were contrary to the Roman legal tradition, and bear the influence of
canon law. The new measures, which were embodied in a new
code called the
Ecloga (
Selection), published in 741, met with some opposition on the part of the nobles and higher clergy. The
Ecloga were a revision and abridgement of the sixth-century
Code of Justinian. The authors of the legal codes of
Basil I () and
Leo VI the Wise () of the
Macedonian dynasty formally rejected the
Ecloga. Leo and his successor
Constantine V transformed the Byzantine
orphanotrophos into a
magistrate. Prior to these legislative reforms,
Byzantine law required that all
orphans are passed into the Byzantine
orphanage or to a
monastery.
Numismatics '' silver coins, first struck by Leo III to commemorate the coronation of his son,
Constantine V, in 720The coins minted during Leo's reign exclusively depicted male imperial dynasts, promoting the dynastic
order of succession. In 721, Leo introduced the
miliarēsion, a silver coin worth one-twelfth of a
nomisma. The
gold coins of
Leo IV the Khazar show posthumous portraits of Leo III. ==Assessment and legacy==