St Nicholas is from Greece. He was a historic 4th-century saint and a bishop in Myra. He was popular for secretly giving gifts like putting coins in the shoes of people who left them out for him, and hence became the model for Santa Claus.
There's an account of it at this URL: Bishop Nicholas Loses His Cool. Basically, Arius was asserting that Jesus Christ was not consubstantial with God the Father; apparently at considerable length (which makes sense since it would be incompatible www.quora.com