I always get annoyed when Christians complain about how Christmas has become so commercialized, and that it should be about Jesus, not Santa. But if you think about it, Santa predates Jesus by a long shot. Read on…(material from Wikipedia, which also has a great entry on Yule, the precursor to Christmas.)
Influence of Germanic paganism and folklore
Numerous parallels have been drawn surrounding the figure of Odin, a major god amongst the Germanic Peoples prior their Christianization. Since many of these elements are unrelated to Christianity, there are numerous theories regarding the pagan origins of various customs of the holiday stemming from areas where the Germanic peoples were Christianized and retained elements of their indigenous traditions, surviving in various forms into modern depictions of Santa Claus.
Odin was sometimes recorded, at the native Germanic holiday of Yule, as leading a great hunting party through the sky. Two books from Iceland, the Poetic Edda, compiled in the 13th century, and the Prose Edda, written in the 13th century by Snorri Sturluson, describe Odin as riding an eight-legged horse named Sleipnir that could leap great distances, giving rise to comparisons to Santa Claus’ reindeer.
Odin’s appearance was often similar to that of Saint Nicholas, being depicted as an old, mysterious man with a beard.
According to Phyllis Siefker, children would place their boots, filled with carrots, straw or sugar, near the chimney for Odin’s flying horse, Sleipnir, to eat. Odin would then reward those children for their kindness by replacing Sleipnir’s food with gifts or candy . This practice survived in Germany, Belgium and the Netherlands after the adoption of Christianity and became associated with Saint Nicholas as a result of the process of Christianization and can be still seen in the modern practice of the hanging of stockings at the chimney in some homes. Children still place their straw filled shoes or stockings by the chimney every winter night, and are rewards with candy and gifts.
This practice in turn came to the United States through the Dutch colony of New Amsterdam prior to the British seizure in the 17th century, and evolved into the hanging of socks or stockings at the fireplace. In many regions of Austria and former Austro-Hungarian Italy (Friuli, city of Trieste) children are given sweets and gifts on Saint Nicholas’s Day (San Niccolò in Italian), in accordance with the Catholic calendar, December the 6th.
Numerous other influences from the pre-Christian Germanic winter celebrations have continued into modern Christmas celebrations such as the Christmas ham, Yule Goat, Yule logs and potentially the Christmas tree.
Pre-Christian Alpine traditions
Originating from Pre-Christian Alpine traditions and influenced to extents by later Christianization, the Krampus is represented as a Companions of Saint Nicholas. Traditionally, young men dress up as the Krampus in the first two weeks of December and particularly in the evening of December 5 and roam the streets frightening children (and adults) with rusty chains and bells.