The celebration of Christmas originated in Rome around 336 AD, but it did not become a major Christian festival until the 9th century. The nativity story of the birth of Jesus Christ is found in the New Testament of the Bible. The name "Christmas" comes from the Mass of Christ, and the celebration did not begin until the fourth century. The date of December 25 was Christianized from the Roman holiday celebrating the winter solstice. ^{britannica.com 1 3 4 2}