Looking up Santa Clause (lawyers' spelling) I found this succinct statement in an old Chamber's Encyclopaedia: "The winter solstice was regarded as the birthday of the sun, and at Rome 25 Dec. was observed as a pagan festival of the nativity of sol invictus. The church, unable to stamp out this popular festival, spiritualized it as the feast of the Nativity of the Sun of Righteousness.--- When Christianity spread northwards, it encountered--- the great Yule-feast of the Norsemen. Once again, Christmas absorbed heathen customs."
Queen Charlotte introduced the Christmas tree, from Germany, to England.