What is Arianism?

Clean Cut: Episode Directory
http://nameunderheaven.blogspot.com/2...

Clean Cut; Episode 353
Who was Bishop Arius? Who was the greatest opponent of Arianism? What happened to Arius at the First Council of Nicaea?
All well-reasoned comments welcome.

If you're new to the series, I hope you'll check out the previous episodes, as they contain a lot of deductions, which I'll be building on.