Constantine I (27 February 272 – 22 May 337 AD) was a powerful general who reigned over the Roman Empire as emperor, until his death. He made the previously named city Byzantium (now Istanbul, Turkey) capital of the whole Roman Empire. As emperor, he named the city Constantinople, which means "City of Constantine" in Greek.
- Before Constantine became Emperor, he was fighting for the throne at the Battle of Melina Bridge. When he saw a cross in the sky with the word sin hoc signor vinces ,he changed his deity from Apollo to Jesus and won the battle.
- In pagan Rome before this, it had been against the law to believe in Christianity, and Christians had been tortured or killed, but Constantine made sure that this stopped, and that they were given their property back. He went on to organize the whole Catholic Church at the Council of Nicea, even though he himself did not get baptized until near the end of his life.
- Constantine was also a big part of the beginning of the Orthodox religion, after changing the point from which he ruled from Rome to Byzantium.
