While St. Nicholas is widely known for his love of gift-giving, he was also a courageous bishop during a difficult time in the Church.
St. Nicholas was the bishop of Myra. a city now located in Turkey, in the early 4th century,
The medieval compilation entitled The Golden Legend explains how he was miraculously chosen to be a bishop after having traveled to the Holy Land:
After...the bishop of Myra died and other bishops assembled for to purvey to this church a bishop. And there was, among the others, a bishop of great authority, and all the election was in him. And when he had warned all for to be in fastings and in prayers, this bishop heard that night a voice which said to him that, at the hour of matins, he should take heed to the doors of the church, and him that should come first to the church, and have the name of Nicholas they should consecrate him bishop.
All the bishops remained in prayer and opened the door of the church, waiting patiently to see if a man named Nicholas would appear.
And this was a marvelous thing, for at the hour of matins, like as he had been sent from God, Nicholas arose tofore all other. And the bishop took him when he was come and demanded of him his name. And he, which was simple as a dove, inclined his head, and said: I have to name Nicholas. Then the bishop said to him: Nicholas, servant and friend of God, for your holiness ye shall be bishop of this place.
Nicholas was shortly thereafter ordained the bishop of Myra.
It is believed that he attended the First Council of Nicaea in 325 and participated in it.
St. Nicholas is often depicted wearing a bishop's miter. The common US depiction of Santa Claus, based on his popularity among early Dutch settlers, is modeled after colonial fur traders.