Athanasius was a Christian bishop and Patriarch of Alexandria, in Egypt. Athanasius and another church leader, 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 the two leaders.
The council decided 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.
This short article about a person or group of people can be made longer. You can help Wikipedia by adding to it.