Speaking of the Winter Solstice, in ancient times, the prolonged darkness and coldness which brought on the very real threat of starvation, was seen as a time of death and rebirth. Early cultures, in their pagan beliefs, held a variety of rituals, rites and celebrations to hurry the sun back. Scandinavia and many parts of northern Europe burnt Yule logs, not just to keep warm but as a symbolic gesture to welcome back the light. (They didn’t have electricity in those days).
In fact, the burning of Yule logs goes back to Nordic tradition where Yule is the name of the Winter Solstice Festival. The log was cut from oak trees and decorated with holly, mistletoe, and evergreens before it was burnt while people feasted on the last fresh meat of slaughtered animals to brave the frozen months ahead. (info sourced from mentalfloss)