In the British Isles, before Christianity became established, as in Rome and Constantinople. the trappings and basic festivity of what became the Twelve Days of Christmas it was the celebration of the Winter Solstice, a Celtic tradition complete with yule logs, holly, and other decorations and festivities. The modern tradition of a Christmas tree comes from Germany, Tannebaum.
Washington Irving and Charles Dickens made famous.
Saint Nicholas legends are about as old as organized Christianity and the development of the first churches that became centralized in Rome and Constantinople, later to remain centralized in Rome. Father Christmas [England] and Kris Kringle, Sinterklass [Dutch], and Santa Claus.
Traditions during the Victorian period reunited the roots of Merry Old England to become established in the United States to include the tradition of carolers.
Robert Burns, Old Lang Syne  became synonymous with New Year's eve celebrations.
A very Merry Christmas to Helen-Marie ...