Back in the days when Europe was pagan, She was the Scandinavian Goddess of the Winter Solstice. Following the longest night of the year, She would bring back the light of the sun, not only to illuminate the darkness, but to ensure human survival.
When Northern Europe was Christianized, the Goddess went undercover (as so many did) and was transformed into a Saint of the Christian church. Her "conversion" to Christianity was entirely superficial, however. Her Feast Day remained on the Winter Solstice and Her rituals continued unchanged. Even Her new "saint name" -- Sankta Lucia -- means "Holy Light."
Later, when Renaissance Europe switched from the Julian to the Gregorian calendar, several days were lost in the process. Lucia's Feast Day under the new calendar ended up as December 13, a week before the Winter Solstice. It has remained there ever since.
At dawn on Sankta Lucia's Day, a Scandinavian daughter wearing the Crown of Light will go throughout the house to greet her family and serve them the bounty of the Goddess -- coffee and special yellow saffron buns which represent the returning light.
So ends the longest night
With light that She's bringing.
She is the Queen of Light
Clad in Her garment white,
Wearing Her crown of light --
Sankta Lucia! Sankta Lucia!
Wishing you all joy and light today!