Saint Nicholas of Myra
Our father among the saints Nicholas of Myra, Wonder-worker, was the archbishop of Myra in southern Asia Minor in the fourth century and is also the basis for the Santa Claus legends and imagery which accompany Christmas celebrations in much of the world.
While widely honored and venerated, not only in the Orthodox Church, but throughout most Christian groups, little is known historically of the life of Nicholas. He is known to have been archbishop of Myra and he may have participated in the Council of Nicea in 325. In addition to being honored as the patron saint of many countries, notably Greece and Russia, and of cities, he is the patron of many occupational groups, most notably of sea-farers. St. Nicholas is commemorated by the Church on December 6, and also on May 9 (the transfer of his relics) and on July 29 (his nativity).
…In time his fame in northern Europe as a saintly bishop began changing to that of a giver of gifts to children, usually done on December 6. As immigrants from the Germanic and Nordic lands settled in the United States the image of St. Nicholas, or "Sinterklaas," as he is known among the Dutch, slowly changed to that of "Santa Claus" with little tie to the spirituality of Christianity.