St. Nicholas of Myra

St. Nicholas of Myra died December 6, 345 (or 352). He attended the Council of Nicaea, where he reportedly struck the arch-heretic Arius because he defamed our Lord. He was immediately banished from the Council and defrocked, but after other bishops all shared a common dream of the Blessed Virgin Mary imploring mercy on him, they re-instated him.

He was well known for his generosity and his love of children and the poor, though he always gave anonymously, sometimes throwing gifts in through windows in the night.
This site has some more details of his life and some of the miracles attributed to him.

The icon above is from St. Catherine's Monastery in Sinai (13th Century).