Flavins Leo I, surnamed the Thracian and the Great, a Byzantine emperor, born in Thrace about A. D. 400, died in January, 474. At the death of Marcian in 457 he was only a military tribune; but being proclaimed emperor by the soldiers, the choice was confirmed by the senate, and he was crowned by the patriarch Ana-tolius, this being the first instance of a prince receiving his crown from the hands of a bishop. He continued the measures of his predecessor against the Eutychians in Alexandria, successfully encountering the opposition of his minister, the Arian chief Aspar, by whose influence he had been raised to the throne. In 466 the Huns invaded Dacia and threatened the eastern empire, but were defeated by the generals of Leo, their principal chief Dengizec, a son of Attila, being killed. In 468 he concerted with Anthemius, the emperor of the West, an expedition against Genseric, king of the Vandals in Africa. Under the command of Basiliscus more than 1,000 ships, each with 100 men, came to land near Carthage, hut were attacked by night with lire ships, and the whole fleet was destroyed or dispersed. This disastrous result was charged upon Aspar, who with one of his sons escaped from a popular tumult only to he assassinated by a band of the emperor's body guard within the precincts of the palace.

The Arian followers of Aspar encouraged the intrigues of Ricimer in the West, and incited the Goths to invade Thrace, and for two years to threaten Constantinople. Among the extraordinary events of this reign were the destruction of Antioch by an earthquake (458), a conflagration in Constantinople (465), immense and destructive inundations (469), and an eruption of Vesuvius (472), which, according to all the historians, was not only felt at Constantinople, hut caused showers of ashes which covered the roofs of houses with a coat three inches thick.