Constantine The Great Flavius Valerius Constantinus, also known as Constantine the Great, was the first Roman emperor to adopt Christianity. He was educated in the imperial court of Rome and pursued to succeed his father. In 305 A.D., his father became the emperor of the Western Empire. But, when he died in 306 A.D., British troops declared that Constantine should replace his father. The Eastern emperor Galerius refused this claim and gave Constantine a lesser rank. The Emperor Constantine I was the sole ruler of the Roman world between 324 and 337 A.D. His reign was one of the most crucial of all the emperors in determining the future course of western civilization. By making Christianity