Final answer:
The eastern half of the early Christian world is known as the Byzantine Empire, centered in Constantinople and characterized by its predominant use of the Greek language. The Eastern Orthodox Church emerged there, especially after the Great Schism of 1054 when it separated from the Roman Catholic Church. This empire's lasting influence is evidenced by the use of the Cyrillic alphabet in some countries.
Step-by-step explanation:
The eastern half of the early Christian world is known as the Byzantine Empire. This region, which spoke Greek, was initially part of the Roman Empire and was centered in the city of Constantinople, now known as Istanbul. After the fall of Rome, the Eastern Roman Empire continued to thrive and preserve many aspects of Roman governance and culture, but it progressively adopted Christianity as a state religion and incorporated it into its social and cultural fabric.
During the reign of Emperor Constantine, Christianity began to flourish, and this led to a critical pivot point for Christian art and architecture. The language of the church services and the official language of the empire was Greek, and over time, this distinguished the Eastern Christian church from the Western church, which used Latin. The split became formalized during the Great Schism of 1054, when the Eastern Orthodox Church, led by the Patriarch of Constantinople, separated from the Roman Catholic Church, which was under the leadership of the Pope in Rome.
The Byzantine Empire had a profound influence on the surrounding regions, and its religious legacy remains visible today, especially in the countries that use the Cyrillic alphabet, derived from Greek, which indicates their conversion to Christianity through Orthodox missionaries. Notably, the Byzantine Empire lasted for nearly a millennium after the fall of Rome, demonstrating its significant historical and cultural longevity.