By the year 732, the Byzantine Empire ruled by Leo III (r. 717-741) who had begun to restore order to the administrative workings of the empire following the Twenty Years’ Anarchy in which numerous emperors were installed and overthrown after the deposition of Justinian II in 711. Leo III was the first emperor of the Isaurian Dynasty and was notable for instituting iconoclasm, the destruction of religious images and icons, within the Byzantine Empire. This led to disputes with the papacy and the wealthier citizens of Italy and Greece. Invasions by the Umayyad Caliphate had been frequent during the turbulent period before Leo III’s reign; however, he managed to launch a series of successful defences after reforming Byzantine military structure. In the west his military endeavours were not as successful against the Lombards. He also facilitated the migration of Slavic peoples into Byzantine territory to fill sparsely populated areas and increase productivity.
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