When canonised (sainted), he became the protector of children and after his death, the legend of St. Nicholas spread.
St. Nick's name became Sint-Nicolaas in Dutch, or Sinter Klaas for short. Which was only a skip, hop and a jump to Santa Claus.
But why do we tell the tale of Santa Claus delivering presents to kids all over the world?
Well Santa delivering presents comes from Hollands tradition of St. Nicholas' Feast day. On December 6 children would leave their shoes out over night and in the morning they would find gifts that were left by Saint Nicholas.
One year, a poor man with three daughters couldn't afford the dowry to have them married. One night Saint Nicholas dropped a bag of gold down the man's chimney so that his oldest daughter could get married. The bag fell into a stocking that was drying by the fire and that's why on Christmas Eve we leave stockings hanging by the fire.