Originating around AD 320 as taught by Arius, Arianism was the theological view that Jesus was divine, but was created by and is lesser than God the Father. Arianism was Christian, but was denounced as heresy by the orthodox trinitarians, or Athanasians (after Athanasius of Alexandria who argued against the Arians at the First Council of Nicaea) , who eventually prevailed. All of the writings of Arius were systematically destroyed by the Church, but historians have reconstructed his thoughts from the arguments used against them by orthodox trinitarians.
Arianism was officially condemned as incorrect by the Council of Nicaea in 325, which gave its seal of authority to the established trinitarian view. On the surface the Arian position appeared to die out, but it simmered under the surface and re-emerged after the death of the Emperor Constantine being cultivated by key bishops and a continued underground in the East. The acceptance by Constantine's son Constantius II of the Arian heresy caused many bishops under his jurisdiction in the Eastern part of the Empire to be exiled and trinitarianism was temporarily suppressed when Constantius took over the Western part of the Roman Empire as well. Even Pope Liberius was exiled. Under Julian the Apostate, the next Emperor, all exiled bishops were allowed back, in part to promote infighting among Christians. Arianism's sudden rise dissipated when Valentinian, a trinitarian became Emperor in the West followed a decade later by Theodius, a trinitarian, in the East. Religious uniformity was again restored when another religious council reiterated that Arianism was a heresy (379).
Never having the numerical support of most bishops, priests or laity to begin with, Arianism died out inside the Empire almost overnight, but continued to be a threat to the Roman Empire as many of the surrounding tribes had and were accepting Christianity, but were converted with an Arian stamp.
The barbarian tribes which invaded Rome, and caused its fall in 476, were often Arians. They include the Visigoths and the Ostrogoths, and especially Theoderic. Centuries passed before the trinitarians prevailed in those regions. The 5th Ecumenical Council in 553 ended the last outreaches of Arianism within greater Europe.
Arianism died out as an organized force but its ideas were known to theologians. Arianism Unitarianism in Renaissance Europe grew out of the teachings of the Italians Lelio Sozzini, or Socinus (1525-1562), and his nephew Fausto (1539-1604) during the period of the Protestant Reformation. Isaac Newton was an Arian--indeed he modeled himself after Arius--but kept it secret because heresy would cost him his official academic and government appointments.
Unitarian ideas that emerged in England and the U.S. after 1770 have many similarities to Arianism.
- Barry, William. "Arianism" Catholic Encyclopedia (1905) online
- Gonzalez, Justo L. A History of Christian Thought: Volume 1: From the Beginnings to the Council of Chalcedon (2nd ed. 1987); excerpt and text search vol 1
- Williams, Rowan. Arius: Heresy and Tradition (2002) excerpt and text search
- "Schaff, P. "Arianism" in New Schaff-Herzog Encyclopedia of Religious Knowledge (1911)online
- J. Herrin, The Formation of Christendom. (1987)