Christmas in Sweden and most of Scandinavia begins on December 13th. The 13 is the feast day of Sankta Lucia (Saint Lucia), bringer of light and patron saint of vision. Born in 283 in Syracuse, Sicily, Lucia was known to bring food and supplies to persecuted Christians hiding underground while wearing a wreath of candles upon her head to light the way.
She was betrothed to a wealthy pagan but vowed to remain unmarried, wanting to dedicate her life to helping others. Refusing to be married and named a Christian, she was tortured by having her eyes removed and finally martyred. Before the Gregorian calendar reform, Saint Lucia’s feast day fell on the winter solstice, the shortest and darkest day of the year in Sweden, a country she is rumored to have visited in her short life. Today, many in Nordic countries and elsewhere continue to honor her as the virtuous bride, bringing joyful light to their dark winter days.
On the morning of her feast day, in family observances, the oldest daughter in each family dresses in a white robe and wears a wreath of candles on her head while delivering sweet rolls (called lussekatt) and coffee to her parents by candlelight.
The sisters of the Lucia Bride wear a wreath of tinsel in their hair and a piece tied around their waist, while the boys have tall pointed caps sprinkled with stars. Awakened by the lights and the singing, the parents arise and eat the breakfast served, thus ushering in the Christmas season.
As Lucia Day comes at the darkest time of year, the candles of the ministering Sankta Lucia portend and witness to the True Light-the birth of Christ. On the morning of the thirteenth of December, the strains of "Sankta Lucia" are heard everywhere in Scandinavia as the white-robed maiden comes out of the night with her burning crown of candles. In honor of her martyrdom, It has long been the custom to donate money on Lucia Day to institutions working for the blind.
Source, including traditional songs and recipes: http://www.angelfire.com/ne/elkhorn38/stlucia.html
The Legend of Sankta Lucia
Christmas in Sweden
Sankta Lucia: The Survival of a Nordic Sun Goddess