The Byzantine Empire existed for nearly 1,125 years, and it’s one of the greatest empires of all time. Many historians have agreed that without Byzantium to protect it, Europe would have been overrun by the tide of Islamic invaders.

Beginning its adult life as the capital for the Eastern part of the Roman Empire, the city of Constantinople—later Byzantium, and Istanbul today—became the center of an extremely vibrant society that preserved Greek and Roman traditions while much of Western Europe slipped into the Dark Ages. The Byzantine Empire protected Western Europe’s legacy until barbarism waned, when finally the preserved Greek and Roman masterworks opened the eyes of Europeans and stoked the fires of the Renaissance.

While Greece was under Roman rule, in 51 AD Christianity had been introduced when Saint Paul preached in Athens on Mars Hill as well as in Thessaloniki and Corinth. Christianity spread the sead of division in the Roman empire which wanned in the next decades.

In A.D. 324 the Emperor of the West, Constantine I, defeated the Emperors of the East, Maxentius and Licinius, in the civil wars of the Tetrarchy. Constantine became the first Christian emperor of the Roman Empire—though the complete conversion of the Roman Empire to Christianity was not accomplished during his lifetime. The construction of the city of Constantinople, however, was one of his absolute triumphs. While other Ancient Greek and Roman emperors built many fine cities during their reign, Constantinople exceeded them all in size and magnificence. It soon became the capital of the Byzantine Empire, and thus marked the dawn of a new era.

Justinian I build Hagia Sophia, which was completed in A.D. 538. It became the center of the Greek Orthodox Church for a number of centuries. This massive cathedral still stands today in Istanbul, and remains one of the largest and most impressive churches in the world.

Most historians agree that after the accession to the Byzantine throne of Heraclius in 610 A.D., the Byzantine Empire became essentially Greek in both culture and spirit. Heraclius made Greek the official language of the Empire, and it had already become the most widely spoken language of the Byzantine population. The Byzantine Empire, having had its origins in the Eastern Roman Empire, now evolved into something new—something different from its predecessor. By 650 A.D., only a very few lingering Roman elements remained alongside the pervasive Greek influence. According to various historical sources, a large majority of the Byzantine population from 650 A.D. onwards was of Greek cultural background. Additionally, the Byzantine army fought in a style which was much closer to that of the Ancient Athenians and Spartans than that of the Roman Legions.

For the next 800 years Byzantine empire withstood against attacks from Turks, Arabs, Franks, Crusaders and pirates with the help of Greek-fire, an explosive and incendiary substance made from sulphur, pitch and petroleum whose effect was the equivalent of what airplanes and tanks had on 20th century warfare.

On 1453 the siege and fall of Constantinople is one of the major events of world history heralding the end of the Byzantine Empire and the beginning of the Ottoman empire. Mehmed the Conqueror, with an army of 150,000 Turks besieges Constantinople and conquers it.

Byzantine Scholars flee the empire to the West bringing with them from Constantinople the knowledge and art that would play a pivotal role in bringing about the Renaissance in Western Europe.