(c.680–741), Byzantine emperor 717–41. He repulsed several Muslim invasions and carried out an extensive series of reforms. In 726 he banned icons and other religious images; the resulting iconoclastic controversy led to over a century of political and religious turmoil.
Definition of Leo III in US English:
Leo III
proper noun
(c.680–741), Byzantine emperor 717–741. He repulsed several Muslim invasions and carried out an extensive series of reforms. In 726, he banned icons and other religious images; the resulting iconoclastic controversy led to more than a century of political and religious turmoil.