[d] During his 17-year rule, he oversaw a number of ambitious political and military plans, aimed mostly at aiding the faltering Western Roman Empire and recovering its former territories.

[13] His Dacian origin[14] is mentioned by Candidus Isaurus,[15][16] while John Malalas believes that he was of Bessian Thracian stock.

He was the last of a series of emperors placed on the throne by Aspar, the Alan serving as commander-in-chief of the army, who thought Leo would be an easy puppet ruler.

[21] His coronation adventus gave a key role to Aspar, who rode with Leo in his chariot during the procession in Constantinople and offered him a golden crown when they arrived at the Forum of Constantine.

The Balkans were ravaged by the Ostrogoths, after a disagreement between the Emperor and the young chief Theodoric the Great, who had been raised at Leo's court in Constantinople, where he was steeped in Roman government and military tactics.

However, none of these attackers had the siege engines necessary to capture Constantinople, whose walls had been rebuilt and reinforced in the reign of Theodosius II.

1,113 ships carrying 100,000 men participated in the expedition, which ended in defeat because of bad leadership from Leo's brother-in-law Basiliscus.

[25] In 472, Leo issued an edict which stipulated that high-ranking officers who permitted pagan sacrifices on their land were to be demoted and have their possessions confiscated.

[citation needed] Leontia then married Marcian, a son of Emperor Anthemius and Marcia Euphemia.

[18] The Georgian Chronicle, a 13th-century compilation drawing from earlier sources, reports a marriage of Vakhtang I of Iberia to Princess Helena of Byzantium, identifying her as a daughter of the predecessor of Zeno.