On Dec. 21, the northern hemisphere celebrates the winter solstice, the shortest day of the year, or the longest night. While it's the darkest time of the year, the day also marks a turning point. From here on out, the the sun shines a little longer each day, and we begin the slow march toward spring.
Fittingly, the winter solstice is celebrated by cultures the world over as a day of hope and resilience, and has figured prominently in religious rituals. For the ancient Romans, the winter solstice was marked by the Saturnalia festival, a week-long celebration where traditional roles were upended amid feasting and drinking. Masters waited on servants, gambling was temporarily legal and the social hierarchy was upended.
In Iran, the solstice was marked by the Yalda night, when families gathered to eat, drink and recite poetry with each other. Foods colored red represented the rising sun and the return of life. The Yule celebration, from which the modern Christmas celebration emerged, was observed in Europe by the Germanic people, and involved hearty foods, drinking, decorations and usually some variation of an elf or old man bearing gifts.