There may have been more practical considerations for choosing 25 December. The choice would help substitute a major Christian holiday for the popular Pagan celebrations surrounding the Winter Solstice (Roman Sol Sticia, the three-day stasis when the sun would rise consecutively in its southernmost point before heading north, 21, 22 and 23 December. In AD 274, Emperor Aurelian had declared a civil holiday on 25 December (the "Festival of the birth of the Unconquered Sun") to celebrate the deity Sol Invictus. Finally, joyous festivals are needed at that time of year, to fight the natural gloom of the season (in the Northern Hemisphere).