During the 3rd century, Greece was invaded by various tribes: Heruli, the Goths, the Alemanni, the Franks, and the Vandals and Sassanians defeated Roman armies several times during the third century. The Pax Romana was endangered. Deep social and economical problems rose through the Empire. Taxes increased to expand or reorganise the army.
In the meantime, Christianity became slowly the Empire’s religion. St Paul came in Greece to proclaim Christianity with his famous “sermon on an Unknown God” in 51 A.D. In 305 AD, Constantine became Emperor of Rome. In 324 A.D., the Emperor Constantine I transferred the capital of the Empire from Rome to Byzantium which took the name of Constantinople.
In 364 AD, the Empire was officially split: the Roman Empire was divided in two parts: the Roman Empire at the west and the Byzantine Empire at the east. The Roman Empire started to decline leaving its place to the Byzantine Empire.
The strategically location of Constantinople, between the Black Sea and the Aegean, allowed the control over East and West Empire.
Even if Constantine gave legitimacy to Christianity, paganism continued to exist. Christianity started to take a material form with a particular architecture, religions, mosaics and even hymns and theological tracts.
In the meanwhile, the west was divided in several kingdoms and the power of the Roman Empire moved definitely to the East.
During the 6th century, the Emperor Justinian expanded the empire’s territory by conquering the southern Levant, northern Africa and Italy. He organized a centralized bureaucracy and a new fiscal system.
But, the Empire was engaged in several wars that left it very vulnerable. Serious threats came both from the East and West. The more serious threat came from the Islamic civilization that started to expand rapidly. The Islamic forces conquered Egypt, Syria, Iraq, Iran, and Afghanistan. Even Constantinople almost felt under the hands of the Muslims.
During the 6th and 7th,...