How is Santa associated with Christmas?

The story is (in short) that a baby was separated from his mother in a fairy forest. Taken in by a kind fairy, he was named Nicholas. As he grew, he discovered a town where he would watch the other children. They were sad, constantly being whipped by soldiers. One day he came back to the village with a huge sack and gave each child a toy. So the children would not become greedy, he would come once a year.