Κωνσταντίνο (Constantine) was a significant historical figure known for being the first Roman Emperor to convert to Christianity. He ruled from 306 to 337 AD and is best known for establishing Constantinople (modern-day Istanbul) as the new capital of the Roman Empire. This city became a major center for trade, culture, and religion. Constantine is also famous for the Edict of Milan in 313 AD, which granted religious tolerance to Christians and allowed them to practice their faith openly. His reign marked a turning point in the history of Christianity, leading to its spread throughout the Roman Empire and beyond.