Holly was the sacred plant of Saturn and was used at the Roman
Saturnalia festival to honor him.  Romans gave one another holly
wreaths and carried them about decorating images of Saturn with
it.  Centuries later, in December, while other Romans continued 
their pagan worship, Christians celebrated the birth of Jesus.  To
avoid persecution, they decked their homes with Saturnalia holly.
As Christian numbers increased and their customs prevailed, holly
lost its pagan association and became a symbol of Christmas.

   The plant has come to stand for peace and joy, people often 
settle arguments under a holly tree.  Holly is believed to frighten 
off witches and protect the home from thunder and lightning.  In
West England it is said sprigs of holly around a young girl's bed on
Christmas Eve are suppose to keep away mischievous little goblins.
In Germany, a piece that has been used in church decorations is
regarded as a charm against lightning. In England, British farmers
put sprigs of holly on their beehives. On the first Christmas, they
believed, the bees hummed in honor of the Christ Child.  The 
English also mention the "he holly and the she holly" as being the
determining factor in who will rule the household in the following
year, the "she holly" having smooth leaves and the "he holly"
having prickly ones.  Other beliefs included putting a sprug of
Holly on the bedpost to bring sweet dreams and making a tonic from holly to cure a cough.  All of these references give light to "decking the halls with boughs of holly."