The Byzantine Empire, also referred to as the Eastern Roman Empire, was the continuation of the Roman Empire in the East during Late Antiquity and the Middle Ages, when its capital city was Constantinople (modern-day Istanbul, which had been founded as Byzantium). It survived the fragmentation and fall of the Western Roman Empire in the 5th century AD and continued to exist 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 created after the end of the realm; its citizens continued to refer to their empire as the "Roman Empire" (, tr. ; ), or "Romania" (), and to themselves as "Romans". 

Several signal events from the 4th to 6th centuries mark the period of transition during which the Roman Empire's Greek East and Latin West divided. Constantine I (r. 324–337) reorganised the empire, made Constantinople the new capital, and legalised Christianity. Under Theodosius I (r. 379–395), Christianity became the Empire's official state religion and other religious practices were proscribed. 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. Thus, although the Roman state continued and Roman state traditions were maintained, modern historians distinguish Byzantium from ancient Rome insofar as it was centred on Constantinople, oriented towards Greek rather than Latin culture, and characterised by Orthodox Christianity.
What is another name for the Byzantine Empire?
In the early days, what was its capital city called?
What is it currently called?
Founded by?
When it was existing, was it the most powerful force?
Where exactly?
What did the citizens called the empire?
and themselves?
What happened from the 4 and 6th centuries?
Who reorganized the empire?
and did he legalize Christianity?
and what was the new capital?
Under whose reign, did Christianity become the official state religion?
Was it the only religion that was practiced?
Under who reign was the administration restructured?
So which language did the use then?
In place of which language?
So, were the Roman traditions kept?
Characterized by what?
Eastern Roman Empire
The Byzantine Empire, also referred to as the Eastern Roman Empire
Constantinople
when its capital city was Constantinople
Istanbul
when its capital city was Constantinople (modern-day Istanbul, 
Byzantium
modern-day Istanbul, which had been founded as Byzantium)
Yes
the empire was the most powerful economic, cultural, and military force in Europe
Europe.
the empire was the most powerful economic, cultural, and military force in Europe.
"Roman Empire"
 its citizens continued to refer to their empire as the "Roman Empire" 
"Romans".
and to themselves as "Romans".
Roman Empire's Greek East and Latin West divided
Several signal events from the 4th to 6th centuries mark the period of transition during which the Roman Empire's Greek East and Latin West divided
Constantine I
Constantine I (r. 324–337) reorganised the empire
yes
and legalised Christianity.
Constantinople
made Constantinople the new capital,
Theodosius I n
Under Theodosius I (r. 379–395), Christianity became the Empire's official state religion 
Yes
Christianity became the Empire's official state religion and other religious practices were proscribed.
Heraclius
Finally, under the reign of Heraclius (r. 610–641), the Empire's military and administration were restructured
Greek
and adopted Greek for official use instead of Latin
Latin.
adopted Greek for official use instead of Latin.
yes
 the Roman state continued and Roman state traditions were maintained
Orthodox Christianity.
 and characterised by Orthodox Christianity.