Decking the halls with boughs of holly and other evergreens did not start off as Christmas ritual at all.
Indeed, this custom goes back to a Roman festival honoring Saturn, the God of Agriculture.
During this celebration, which was held around December 25, Romans would fill thier homes with greens and give each other holly wreaths as symbolds of friendship.
In later years, the first Christians (who had to practice thier new religion in secret) hung holly and greens on thier front doors to mask thier beliefs from the Romans.
After a while, the Christians adoped the custom as their own, and now wreaths, boughs and garlands remain a favorite part of Christmas festivities.