What is the Nativity?

During the holiday season, the word "nativity" becomes a popular word synonymous with presents, reindeer, and sugar plums. But what role does the nativity play in the realm of the popular story of the newborn? According to Oxford Reference Online (ORO), the nativity refers to the story of Jesus' birth beginning with the prophecies announcing the birth of jesus, Mary and Joseph's journey to Bethlehem, followed by the struggle to find a place to sleep for the night and the subsequent birth. ORO also states that starting in the 4th century, christmas was celebrated on the 25th of December. 

Christian de Mérindol "Nativity"  Encyclopedia of the Middle Ages. Ed. André Vauchez. © 2001 by James Clarke & Co. Encyclopedia of the Middle Ages (e-reference edition). Distributed by Oxford University Press.  Central Washington University.  8 December 2010  <http://www.oxfordreference.com/views/ENTRY.html?subview=Main&entry=t179.e1940>