Here are a few interesting bits of information from Brewer's Dictionary of Phrase & Fable.
A long time ago the Roman festival of Saturn was held in December and the temples were decorated with greenery.
The druids are associated with mistletoe, and the Saxons used holly and ivy.
These customs have been transferred to the Christian festival.
The decorated Christmas tree was in use among the Romans and was introduced to Britain from Germany soon after Queen Victoria's marriage with Prince Albert of Saxe-Coburg-Gotha in 1840.
