The history of the Christmas tree goes back centuries and varies by region and culture. However, the most commonly accepted origin of the Christmas tree can be traced back to medieval Germany, where it was originally called the "paradise tree" and was decorated with apples to symbolize the Garden of Eden. In the 16th century, Martin Luther, a German theologian and reformer, is credited with popularizing the Christmas tree by adding lights and ornaments to it. Since then, the tradition of decorating Christmas trees has spread around the world, becoming a beloved symbol of the holiday season.