Athanasius was a Christian bishop and Patriarch of Alexandria in Egypt. Athanasius and another Church leader named Arius disagreed about the theology of Jesus. Emperor Constantine the Great had the leading priests of Christianity go to the First Council of Nicea to debate which of the two was right. They said that it was Arius, so Arius’s theology became the Nicene Creed which Athanasius opposed. Athanasius’s religious belief is called the Athanasian Creed.