Back in 2005 I wrote about the seeming arbitrariness (but not the unimportance) of celebrating the birth of Christ on December 25. But even if that date wasn’t the actual calendar day of Jesus’ birth, it’s still interesting to understand why we have come to commemorate it then.

A few years ago Elisha Coffman posted a short article on Christianity Today’s Christian History site about how December 25th became the day. Here’s a good summary of what determined it:

December 25 already hosted two other related festivals: natalis solis invicti (the Roman “birth of the unconquered sun”), and the birthday of Mithras, the Iranian “Sun of Righteousness” whose worship was popular with Roman soldiers. The winter solstice, another celebration of the sun, fell just a few days earlier. Seeing that pagans were already exalting deities with some parallels to the true deity, church leaders decided to commandeer the date and introduce a new festival.

Western Christians first celebrated Christmas on December 25 in 336, after Emperor Constantine had declared Christianity the empire’s favored religion.

Elisha ends with a helpful thought addressing the concern that too many Christian Christmas traditions are “just paganism wrapped with a Christian bow.”