Roman Empire after remaining in-tact for many years,faced treats of division at the death of Emperor Constantinople,who legalized Christianity in 313A.D and moved the capital to the Greek city of Byzantine,naming it Constantinople,to celebrate the victory over eastern and western parts of Roman land in 328A.D.Soon after his death there were tussles among the rulers.Some managed to rule jointly but not as sole emperor.Only Theodosius the great,an Emperor from East succeeded in ruling as a sole emperor but when he died,the empire was divide into two clear-cut division namely Western Roman Empire and Eastern Roman or Byzantine Empire.The former ended in 476 A.D due to their rulers incompetency to greater extent.The latter continued to survive till 1453 A.d.The reason why Byzantine Empire survived , was due to its location .The centre of Empire Constantinople was at the mouth of Black Sea .The Empire was itself protected from three sides by Mediterrenean Sea and had driven the inner threats Gauls out of Greece and Italy.The other threat was the Arabs,who reached Mesopotamia,Syria and Egypt successfuly but were unable to take over the Constantinople from sea.For the time being the threat was removed as the Arabs were involve in civil wars of about 200 years, followed by the Crusades in Europe.In the meantime the Eastern Orthodox Church broke up with the Church of Rome ,now it was politically controlled by the Byzantine Empire.The Ottomon Turks organized themselves and made a clean sweep across Asia minor and took the Fortress of Niceaea,opposite to Constantinople by 1071 A.D. At last,after a series of bloodshed ,the Eastern Empire ended in 1453 A.D.
