Paraphrase

The Byzantine Empire was the predominantly Greek-speaking continuation of the Roman Empire during Late Antiquity and the Middle Ages. Its capital city was Constantinople (modern-day Istanbul), originally known as Byzantium. Initially the eastern half of the Roman Empire (often called the Eastern Roman Empire in this context), it survived the 5th century fragmentation and collapse of the Western Roman Empire and continued to thrive, existing for an additional thousand years until it fell to the Ottoman Turks in 1453. During most of its existence, the empire was the most powerful economic, cultural, and military force in Europe. Both "Byzantine Empire" and "Eastern Roman Empire" are historiographical terms applied in later centuries; its citizens continued to refer to their empire as the Roman Empire.

Several events from the 4th to 6th centuries mark the transitional period during which the Roman Empire's east and west divided. In 285, the emperor Diocletian (r. 284-305) partitioned the Roman Empire's administration into eastern and western halves. Between 324 and 330, Constantine I (r. 306-337) transferred the main capital from Rome to Byzantium, later known as Constantinople "City of Constantine" and Nova Roma "New Rome". Under Theodosius I (r. 379-395), Christianity became the Empire's official state religion and others such as Roman polytheism were proscribed. And finally, under the reign of Heraclius (r. 610-641), the Empire's military and administration were restructured and adopted Greek for official use instead of Latin. In summation, Byzantium is distinguished from ancient Rome proper insofar as it was oriented towards Greek rather than Latin culture, and characterised by Orthodox Christianity rather than Roman polytheism.

The Emperor of the Eastern Roman empire, Justinian, looked at his empire and saw that the laws were a mess. Because they weren't written down, the laws in one part of the empire might be different than the laws in another part of the empire. Justinian wanted all of his people to be treated the same way, so Justinian had his judges and lawyers get together and write down all the laws of the land. They also wanted to write down the laws that began in ancient Rome, the laws called the Twelve Tables. Once they had written down all the laws and made sure that laws did not conflict with each other, they gave this body of law a name. They called it the Justinian Code.

In around the year 330, Constantine moved the political capital of the Roman Empire from Rome to Constantinople. From there, he managed to rule the entire empire. However, this was no easy task, and soon the empire broke down into Western and Eastern Empires, each with their own emperors. In fact, Theodosius, who died in 395 CE, was the last emperor to rule over both halves. With their own emperors, and being separated by geography, the two halves grew further and further apart. Making matters worse, the Western Empire (Rome and its surrounding areas) were continually invaded by the barbarians from the North, while the Eastern Empire (now known as the Byzantine Empire) thrived.

Adding to the disunity, the Church cultures of the East and West had become vastly different. While the Western Empire clung to Latin, the Eastern Church adopted Greek. Before long, even the Eastern Bishops no longer spoke Latin, and the Western Church had never used Greek in its ceremony. As the language barrier grew, so did the differences in church practices. For instance, the two couldn't agree on which type of bread to use in communion.