Dr Mary Cunningham explores what we know of Arius of Alexandria (d. 336) and his theology. Born in North Africa, he was a presbyter of the church of Alexandria and a very popular preacher. His presentation of the question who is Jesus in relation to God the Father was the occasion for disputes in Alexandria with his bishop, Alexander, and others such as Athanasius – and threatened to split the church. At the same time, the Emperor Constantine wanted a united Christian religion as a bonding force within his empire and called the Council of Nicaea (325) whose impact on the notion of a single Christian orthodoxy in theology is still felt today.
Other videos you may find useful;
Why Study the Orthodox Churches of the East with Mary Cunningham https://www.youtube.com/watch?v=iXHX5xtgjIA
Why Study Orthodoxy with Mary Cunningham https://www.youtube.com/watch?v=JzEF96E3wWY
Theologians in Conversation; the Theology of the Trinity https://www.youtube.com/watch?v=02GkSAYu-V8