<P> The East - West Schism, known also as the Great Schism (though this latter term sometimes refers to the later Western Schism), was the event that divided Christianity into Western Catholicism and Greek Eastern Orthodoxy, following the dividing line of the Empire in Western Latin - speaking and Eastern Greek - speaking parts . Though normally dated to 1054, when Pope Leo IX and Patriarch of Constantinople Michael I Cerularius excommunicated each other, the East - West Schism was actually the result of an extended period of estrangement between the two Churches . </P> <P> The primary claimed causes of the Schism were disputes over papal authority--the Pope claimed he held authority over the four Eastern patriarchs, while the patriarchs claimed that the Pope was merely a first among equals--and over the insertion of the filioque clause into the Nicene Creed . Most serious (and real) cause of course, was the competition for power between the old and the new capitals of the Roman Empire (Rome and Constantinople). There were other, less significant catalysts for the Schism, including variance over liturgical practices and conflicting claims of jurisdiction . </P> <P> The Byzantine Empire was the Greek - speaking, Eastern Roman Empire during the Middle Ages, centered at its capital in Constantinople . During most of its history it controlled provinces in the Balkans and Asia Minor . The Eastern Roman Emperor Justinian for a time retook and restored much of the territory once held by the unified Roman Empire, from Spain and Italy, to Anatolia . Unlike the Western Roman Empire, which met a famous if rather ill - defined death in the year 476 AD, the Eastern Roman Empire came to a much less famous but far more definitive conclusion at the hands of Mehmet II and the Ottoman Empire in the year 1453 . Its expert military and diplomatic power ensured inadvertently that Western Europe remained safe from many of the more devastating invasions from eastern peoples, at a time when the still new and fragile Western Christian kingdoms might have had difficulty containing it . </P> <P> The magnitude of influence and contribution the Byzantine Empire made to Europe and Christendom has only begun to be recognised recently . The Emperor Justinian I's formation of a new code of law, the Corpus Juris Civilis, served as a basis of subsequent development of legal codes . Byzantium played an important role in the transmission of classical knowledge to the Islamic world and to Renaissance Italy . Its rich historiographical tradition preserved ancient knowledge upon which splendid art, architecture, literature and technological achievements were built . This is embodied in the Byzantine version of Christianity, which spread Orthodoxy and eventually led to the creation of the so - called "Byzantine commonwealth" (a term coined by 20th - century historians) throughout Eastern Europe . Early Byzantine missionary work spread Orthodox Christianity to various Slavic peoples, amongst whom it still is a predominant religion . Jewish communities were also spread through the Balkans at this time, while the Jews were primarily Romaniotes . In a sense of a Greek - influenced "Byzantine commonwealth", the Greek Christian culture and also the Romaniote culture have influenced the emerging cultures both the Christian and the Jewish cultures of the Balkans and of Eastern Europe . </P>

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