Leo I, also known as "the Thracian", was Roman emperor of the East from 457 to 474. He was a native of Dacia Aureliana near historic Thrace. He is sometimes surnamed with the epithet "the Great", probably to distinguish him from his young grandson and co-augustus Leo II.
Possible alabaster head of Leo on a modern bust
16th cent. Russian Icon depicting St. Leo's enshrinement of the Robe of the Theotokos in Sts. Peter and Mark church, Blachernae
The Byzantine Empire, also referred to as the Eastern Roman Empire, was the continuation of the Roman Empire centered in Constantinople during Late Antiquity and the Middle Ages. The eastern half of the Empire survived the conditions that caused the fall of the West in the 5th century AD, and continued to exist until the fall of Constantinople to the Ottoman Empire in 1453. During most of its existence, the empire remained the most powerful economic, cultural, and military force in the Mediterranean world. The term "Byzantine Empire" was only coined following the empire's demise; its citizens referred to the polity as the "Roman Empire" and to themselves as "Romans". Due to the imperial seat's move from Rome to Byzantium, the adoption of state Christianity, and the predominance of Greek instead of Latin, modern historians continue to make a distinction between the earlier Roman Empire and the later Byzantine Empire.
Gold solidus of Leo III (left), and his son and heir, Constantine V (right)
Constantinople was the largest and wealthiest city in Europe throughout late antiquity and most of the Middle Ages until the Fourth Crusade in 1204.
The seizure of Edessa (1031) by the Byzantines under George Maniakes and the counterattack by the Seljuk Turks
Alexios I, founder of the Komnenos dynasty