Well, let's start with the oldest written accounts of civilizations known to us ~ the Egyptians and the Sumerians. The Twelve Days of Christmas all began with the celebration of the rebirth of Horus or Marduk. Both lasted a total of twelve days. The Sumerian twelve day battle of Marduk to conquer the deities of darkness gave way to the tradition of gift giving. During this celebration, the Sumerians held large parades much like the ones we have today around this time of the year and also exchanged gifts while wishing all good tidings. Many other civilizations subsequently adopted the Winter Solstice such as the Greeks who chose to honor Zeus and his victory over the god Kronos and, as mentioned before, the Romans who honored Mithras during the celebration of Saturnalia.
It is also known that the Christmas tree is very much Pagan in origin, but it was Germanic Pagans who decided to add ornaments to their trees which symbolized the Sun in anticipation of the warmth yet to come. Even modern day decorations such as bells, holiday candles, and wreaths are continuing reminders of our Pagan ancestors. Bells were thought to ward off evil spirits, much like turnips and lighted Jack-o-Lanterns were used at Samhain by the ancient Celts. Evergreens of all kinds are very powerful as they survive the cold, harsh winter months hence symbolizing their importance over death itself. Wreaths symbolize birth, death and rebirth ~ the cycle of the Wheel of the Year.
One of the most endearing of all; however, is the story of the snowflake. The reason behind the belief that they are symbols of love came from the Greek legend about the Goddess Demeter who was said to have cried tears of sorrow after Persephane's decent into the Underworld. These tears formed the first version of snowflakes. There are other similar stories which come from the Sumerians about the Goddess Inanna and so on throughout history.
Kissing underneath the mistletoe? Mistletoe was sacred to the Celts and used for fertility and abundance and when hung over a doorway was protection from evil. The kissing part actually came from the Norse tradition and their custom to receive the blessings of Freya. Blessings of luck, love, fertility and protection from sickness or disease. Reindeer also had a very special meaning to the Celts with the stag being the symbol of Cernunnos.
And finally Santa whose image was originally taken from the Celtic version of The God and the Norse God Odin. His depiction survived throughout the years, although thanks to a clever advertising campaign in the 1930's, has undergone a few minor changes such as his pipe, his elves, etc.
So my friends, why am I giving you all of this information? Well, it is only because I merely have a huge fascination with history and I find it extremely interesting to learn about how we came to our modern beliefs. Do I feel this diminishes the holidays of Christmas or Yule in any way? Certainly not. I feel it simply adds to the splender of the season knowing how these wonderful traditions lived on throughout time.