The Council of Nicea Constantine was the emperor in Rome at the time when he called the Council of Nicea in 325 CE. Constantine was originally a worshipper of the sun god. Later in his life he converted to Christianity. His reign marked the beginning of the joining of church and state. The pagans no longer persecuted Christians. Instead, Christians persecuted others, including other Christians. Christians killed more Christians in the first century after the Council of Nicea than pagans had killed in the century before Nicea. One year after calling the Council of Nicea Constantine had his own son, Crispu