The history of Christmas is something to learn, because Christmas as we know is a relatively new phenomenon.
The celebration of Christmas as a joyous commemoration of peace, love and the advent of Jesus Christ has only been in popularly celebrated since about the 1820's when a book called The Keeping of Christmas at Bracebridge Hall was published by Washington Irving. Published in 1834, by Charles Dickens 'A Christmas Carol' further supported the notoriety and popular celebration of the Christmas Holiday. The popularity of this book was so potent that it is still synonymous with Christmas to this day.
Other common signs of the season like the Christmas trees, mistletoe wreathes, lights, and Santa Clause or Father Christmas are even newer in the history of Christmas celebrations. The earliest Christmas traditions were much more religiously oriented and solemn than today's joyful Christmas parties. Celebrated any time from March to December the earliest Christmas celebrations were passed in fasting, not feasting.
The date universally recognized, December 25th, as marking the birth of Christ and officially opening the Christmas season was contested for hundreds of years. Because the earliest Christians didn't celebrate Christmas, and over one hundred years elapsed before Telesphorus, the second Bishop of Rome, declared that a special church service would be held to mark and hallow the birth of Jesus. No one was sure of the date of Christ's birth so the celebration and week of worship was held in September. From this time on Christmas was held in one fashion or another, but the date was not fixed.
The Date of December 25th and the name Christmas didn't come into existence until 325 AD. It was Constantine the Great who declared December 25 as the official birth date and proclaimed the observance of what he termed Christmas that was not the be moved each year. This was done in part to replace and sweep away the last vestiges of the pagan holidays that had traditionally celebrated during the winter solstice.
The assimilation or resignation to the popularity of the Christian observance of Christmas has been a theme. For example, Christmas celebrations were once banned by leaders of churches and nations. Notable bah-humbuggers include Oliver Cromwell who banned Christmas from 1649-1660. Now secular and religious leaders participate freely and even encourage celebration the Nativity.
Other signs of assimilation include lights, Christmas trees and even mistletoe. These Christmas traditions all have their birth in the pagan celebration of the Festival of Lights during the winter solstice. Early Christians participated in these celebrations to avoid harsh persecution of the time. As Christianity became the prevailing custom, these traditions took on new Christian meanings.
As for our modern celebrations, they are joyful family centered and the source of childhood memories and magic that last a lifetime. The history of Christmas is a great reminder of those that have come before us. What ever your celebrations include may they be merry and bright.