LEO III (surnamed the ISAURIAN), By zantine emperor: b. in Isauria, but by some authorities in Germanicia, in the Syrian province of Commagene, about 680; d. 18 June 741. He entered the army of Justinian II, rose to distinction and under Anastasius 'II became supreme commander of the army in Asia. In 716 he marched against Theodosius HI, who had been proclaimed emperor on the deposition of Anastasius II, and himself seized the crown in 717. His accession was immediately followed by 'the siege of Constantinople by the Saracens under the caliph Solyman, and his stubborn resistance not only compelled the enemy to withdraw after a siege variously estimated at from one to two years, but removed from eastern Europe the danger of a Saracen in vasion. He then proceeded to consolidate his empire, strengthening his frontiers by the en couragement of settlers in the war-ravaged dis tricts, and so thoroughly reorganized his armies that he was able to visit heavy defeats upon the Saracens when in 726 and 739 they again attempted invasion, He instituted civil reforms in taxation, marital and maritime laws and raised the serfs into a class of free tenants.
An uprising against Leo, headed by the deposed Anastasius II, soon after the siege of Con stantinople, resulted in the capture and execu tion of Anastasius. One of the most notable acts of Leo's reign was the order, in 726, that all image-worship in the churches must cease. (See IconocLasis). He was supported by the aristocracy and a portion of the clergy, but op posed by most of the theologians and the nionks. The edict caused a general revolution throughout the empire, and resulted in the loss of Ravenna, Rome and other portions of south ern Italy and the separation of the Greek from the Latin Church. While partially unsuccessful in his attempt at religious reform the reign of Leo is on the whole noteworthy for its solid achievements. He is credited with so stabilizing the empire as to have been the means of its survival for the succeeding 500 years. Con sult Gibbon, 'Decline and Fall of the Roman Empire' ; Bury, 'The Later Roman Empire' (1889) ; Hodgkin, F., 'Italy and Her Invaders' (1892).