Today, December 21, is the Winter Solstice. That mean's a couple of things: today is the shortest day of the year, tonight is the longest night of the year, and today is the first day of Winter. Lots of different cultures celebrate this time of year with some kind of fire ritual.
The great solstice fire festivals of ancient Europe lived on during the Twelve Days: Yule Logs, bonfires, torches, and ceremonial candles were all still burned to secure good fortune, fertility for livestock, and bountiful crops in the new year. The smaller household Yule log was usually burned during the Twelve Nights, or for at least a minimum of twelve hours. The wood of the Yule log itself was steeped in special powers: the prior year's ashes were strewn over the fallow fiels during the Twelve Days to ensure the vigor of next year's crops; the number of sparks when the log was stoked predicted the number of calves, piglets, chicks, etc. in the spring; a piece of the log's charred remnants was saved to protect the house from lightning during thunderstorms - to name just a few beliefs! The charred remnant was finally used to kindle the new log at the beginning of the next Twelve Days.
In some places, a massive candle was burned instead - its light must not go out on its own or the luck of the family would be "blown away." In other areas, bonfires were lit on Twelfth Night and, in simulation of the life-giving power of the sun, villagers ran with blazing torches throughout the fields and orchards to promote a good harvest.
The Yule Log was also important to protect households from Odin's entourage of unearthly creatures, who were feared to roam the earth during the Twelve Nights. It was also a bad omen if the Yule Log burned out before the end of the Twelve Days.
The Yule Log is one of the most deep-rooted and widespread customs still enjoyed today - from the more traditional Yule Logs still burned in families' fireplaces to the buche de noel cake decorated to look just like a log ready for the fire, to the televised burning Yule log broadcast on Christmas for those without a fireplace of their own.
The Mesopotamians held an annual festival for the twelve days surrounding the winter solstice to cheer on their sun god as he battled to conquer the monsters of darkness and chaos. The ordinary social distinctions were suspended for the duration of the victory celebrations, and parades and masquerades were held where everyone mingled together. The ancient Persians held a similar solstice celebration with bonfires burning all night to help their god of light and day defeat the evil god of darkness and night.
In the lands of the ancient Slavic tribes, both sun gods and sun goddesses were revered. Their winter solstice festivals lasted ten to twelve days and were a time when Slavs honored their departed ancestors with fires to keep them warm and feasts to keep them fed, hoping to elicit their assistance in defeating the dark forces that were overpowering the old sun. Young men dressed in animal costumes (bears and horned animals such as goats and stags) and went about singing and shouting to chase away the evil spirits of winter.