The Eastern Roman Empire (later called the Byzantine Empire) was the eastern half of the Roman Empire that survived the fall of the West in 476. Its capital was Constantinople (now Istanbul), and it lasted from the 4th century (after Theodosius' administrative division in 395) until 1453, when the Ottomans took the city. Roman in laws and institutions, Greek in language and culture, and Orthodox Christian in religion, it was a bridge between Antiquity and the Middle Ages: it preserved Roman law (the Code of Justinian), classical knowledge, the art of mosaics and icons, and acted as a great power in the eastern Mediterranean and the Balkans for over a thousand years. The Byzantine Empire preserved the Roman heritage (law, administration, Greco-Christian culture) with its capital in Constantinople and, from there, had a decisive influence on Slavic Europe: in 988, Kievan Rus adopted Orthodox Christianity from Byzantium, which brought liturgy, icon art, and the written tradition that led to the Cyrillic alphabet; after the fall of Constantinople (1453), Moscow presented itself as its spiritual successor—the “Third Rome”—reinforced by the marriage of Ivan III to Sophia Palaiologina and symbols such as the double-headed eagle, so that Orthodoxy, part of the culture and a certain sacred idea of power in Russia, has its roots in Roman-Byzantine continuity.