Byzantine Empire
Then, another enemy appeared, the Arabs. The Byzantines did not have much money to spend on war because of their battles with the Persians and so they could not withstand the Arabs. Palestine, Syria and Egypt were lost between 635 and 645 by Heraclius. However, the Byzantines defended Asia Minor (now in Turkey), and the Arab advance stopped there. Heraclius ordered the use of Greek as the only language of the empire, erased forever the name "Eastern Roman Empire" and cut the last links with Rome.