When did the first recorded Christmas celebration take place?

Christmas (or the Feast of the Nativity) is an annual festival commemorating the birth of Jesus Christ, observed primarily on December 25 as a religious and cultural celebration by billions of people around the world.

The nativity sequences included in the Gospels of Matthew and Luke prompted early Christian writers to suggest various dates for the anniversary. Although no date is indicated in the gospels, early Christians connected Jesus to the Sun through the use of such phrases as "Sun of righteousness." The Romans marked the winter solstice on December 25. The first recorded Christmas celebration was in Rome on December 25, AD 336. In the 3rd century, the date of the nativity was the subject of great interest. Around AD 200, Clement of Alexandria wrote:

"There are those who have determined not only the year of our Lord's birth, but also the day; and they say that it took place in the 28th year of Augustus, and in the 25th day of the Egyptian month Pachon (May 20) ... Further, others say that He was born on the 24th or 25th of Pharmuthi (April 20 or 21)."

Various factors contributed to the selection of December 25 as a date of celebration: it was the date of the winter solstice on the Roman calendar and it was nine months after March 25, the date of the vernal equinox and a date linked to the conception of Jesus (celebrated as the Feast of the Annunciation).