Why do historians consider constantine 1 the founder of the byzantine empire

d. He moved the capital of the roman empire from Rome to Byzantium, which would be the capital of the byzantine empire for more than 1,000 years.

Explanation:

Constantine I was the first Roman emperor who openly supported and even converted to the Christian religion. His permission for religious freedom allowed the Christian believers to openly and freely practice their religion despite the fact that he himself was a nonbeliever at first.

But more than his religious conversion, he was known greatly as the emperor who shifted the capital of the Roman empire from Rome to Byzantium. In the initial stages of his rule, he created / founded a new imperial residence at Byzantium which later came to be known as Constantinople. This move of shifting the capital from Rome to Byzantium in 330 CE, along with his legalization of Christianity and eventual acceptance of the religion as his personal faith all made him a major name in the history of Rome as the founder of the Byzantine empire.