The origins of Christmas are rooted in a variety of different traditions and beliefs, dating back thousands of years. The most widely recognized origin of Christmas is the celebration of the birth of Jesus Christ, the founder of Christianity. The holiday was first observed by Christians in the fourth century, although the date of December 25 was not set until the year 354. Prior to this, there were several other holidays and traditions that were celebrated during the winter solstice, which was often seen as a time of rebirth and renewal.