The Byzantine Empire spanned from 300 AD to 1500 AD, originating as the eastern portion of the Roman Empire centered around Constantinople between the Black and Mediterranean Seas. It was a multicultural Christian state comprising the Balkans, Asia Minor, North Africa, Syria, with populations including Greeks, Arabs, Jews, Christians, Slavs, and Turks. Constantinople was highly defensible due to its location and fortified walls. The Byzantine Empire had a complex religion that was deeply ingrained in daily life and a source of theological debates and controversies. Over time, the Byzantine Empire emerged as a major world culture, the medieval continuation of Greek and Roman states, culturally and religious