The 13th of December we are celebrating Lucia here in Sweden, 
a tradition  which really lightens  up the darkness this time of year.

Lucia is a festival occurring on December 13, or Lucia Day.
Lucia is a young girl, wearing a white garment and with a Lucia crown
with candles on her head. She is followed by a number of girl attendants, 
also dressed in white and with candles in their hands. 
There are also boys, 'star-boys', participating in the ceremony. 
They, too, are dressed in white and they wear pointed caps.
Lucia and her attendants visit places like schools, hospitals, offices
and churches and sing traditional songs like Sankta Lucia. 
They may also bring coffee, gingerbread biscuits and
'Lucia cats', a kind of saffron bun. 

The Lucia tradition is based on the legend of a pious Sicilian girl
who wanted to devote her life to God instead of marrying.
When she refused the proposal of a nobleman she was killed,
and subsequently she became a martyr

They are singing a very old song in Swedish:

~Sankta Lucia~
'Natten går tunga fjät
rund gård och stuva
kring jord, som sol förlät,
skuggorna ruva
Då i vårt mörka hus,
stiger med tända ljus,
Sankta Lucia, Sankta Lucia.
Natten går stor och stum
nu hörs dess vingar
i alla tysta rum
sus som av vingar
Se, på vår tröskel står
vitklädd med ljus i hår
Sankta Lucia, Sankta Lucia

Mörkret ska flyta snart
ur jordens dalar
så hon ett underbart
ord till oss talar
Dagen ska åter ny
stiga ur rosig sky
Sankta Lucia, Sankta Lucia'

  Sankta Lucia in English    

'The night goes with weighty step
round yard and steading
round earth, the sun departs
leave the woods brooding
There in our dark house, 
appears with lighted candles
Saint Lucia, Saint Lucia

The night goes great and mute
now one hears its wings
in every silent room
murmurs as if from wings
Look at our threshold stands
white-clad with lights in her hair
Saint Lucia, Saint Lucia

The darkness shall soon depart
from the earth's valleys
thus she speaks
a wonderful word to us
The day shall rise anew
from the rosy sky
Saint Lucia, Saint Lucia'

  

The well known Lucia coral are from the beginning an Italian 
melody, by Teodoro Cottrau (1827-79), 
and the Swedish text is written by Sigrid Elmblad in 1924

The tradition was brought to Sweden by the Germans several 
hundred years ago, and it´s  was called the Kinkenjes (Baby Jesus).
Every year a Lucia is representing Sweden, but every town choose
their very own Lucia to represent them.

Some facts from here