Christmas is the 'Mass of Christ'(Mass being
a religious festival) and is the time when
Christians everywhere celebrate the
Nativity i.e. the birth, of Jesus Christ.
Long before Jesus was born, evergreen trees
played an important part in winter festivals.
Pagans decorated their homes with them and
in cold, northern countries, people hung
them in their homes because they thought
that the woodland spirits lived in them and
would thus be protected from the cold. It's
said that Martin Luther first put candles on
a Christmas tree to remind people of the
stars that shone in the night sky of
Bethlehem on the night that Jesus was born.

Landranger Grid Reference SJ876855