Byzantine Empire

The Byzantine Empire (395–1453 CE) was the continuation of the eastern Roman Empire after the division of 395 CE. With its capital at Constantinople (modern Istanbul), it preserved Roman law, Greek culture, and Christian theology through the European 'Dark Ages,' shaping Russian, Balkan, and Middle Eastern civilization. At its peak under Justinian I (527–565 CE), it reconquered much of the western Mediterranean. Byzantium bequeathed the Cyrillic alphabet (via Saints Cyril and Methodius), Eastern Orthodox Christianity, Roman law (Justinian's Code, which forms the basis of many European legal systems), and preserved classical Greek texts that re-entered Western Europe during the Renaissance. Constantinople fell to Ottoman Turks under Mehmed II on May 29, 1453 — ending the empire that had lasted 1,058 years.