Leo III and his advisers were convinced, that the reasons for the unfavorable course of affairs of the empire are to be found in religion, in relationship with God. From the beginning of its existence, the Byzantine Empire aspired to the role of a promoter of the Christian faith, his people were to be chosen by God for the salvation of the rest of the world. The reason, for which God turned his back on the Byzantines, was – according to Leon's associates – cult icon, which has spread from approx. VI w., both among the clergy, as well as the common people. So the emperor initiated the movement of iconoclasm or iconoclasm, ongoing next 100 years. It is accepted, that this state of affairs could have been greatly influenced by the Muslim religion, more specifically those Arab countries, ruled by the Omayyad dynasty, where the fight against the cult of all images of the human figure was undertaken. In the Byzantine Empire, iconoclasm often took brutal forms, the fight was often bloody and ruthless. As long as these lay people were not persecuted in the beginning, who silently at home still worshiped the icons, in the later period, they were often mutilated, banished, and even murdered. The case with the clergy was even worse. The papacy was reluctant to observe the actions of emperors who were supporters of iconoclasm, because it was a manifestation of interference in the independence of the Church, into its doctrinal sphere.
Successor of Leo III, Konstantyn V, defeated w 746 r. Arabs at the Battle of Germanicea (Maras today), and this success only strengthened the conviction of the followers of iconoclasm that the chosen path was right. It seemed, that God became more favorable to the Byzantines. Additionally, the following year a victory over the Arab fleet was achieved, which forced the reflection of those who so far doubted the iconoclastic movement, and the emperor himself treated both of these successes as proof of the correctness of theological views adopted from his father. As long as this only issued an edict ordering the destruction of all holy images, so much Constantine called St. 754 r. council, on which he declared, that the worship of icons is at odds with the teaching of the Church and that the practice will be a curse.
Syn Konstantyna, Leon IV, it softened the new laws somewhat and allowed local cults of images, realizing, that the disruption of society will lead the state to catastrophe. The new emperor did not rule for long, he died in 780 r., and his wife and successor – Empress Irena, who exercised regency on behalf of the minor Constantine VI, even led to the convening of 787 r. Council of Nice (today Iznik), who condemned iconoclasm and thus restored the cult of sacred images. Now, in turn, the hitherto persecuted supporters of the cult began to take revenge on their former oppressors, which disliked the empress who wanted peace and unity in the state, needed to deal with the Arabs pushing back against Asia Minor and the bold Bulgarians. Emperor Leo V returned to iconoclasm at the synod of 815 r., ale zasięg i bezwzględność zwolenników ruchu nie były porównywalne z tymi z czasów Konstantyna V. Obrazoburstwo skończyło się całkowicie wraz z uchwaleniem na synodzie z 843 r. (under Empress Theodora) restoration of the cult of holy images, but until the end of the empire, its society was divided into supporters and opponents of the worship of icons.