Of course, it's also the day when Christians celebrate the birth of Jesus, the centerpiece of their religion and immovable cornerstone of their faith. But did you know that December 25th was more or less randomly chosen?
Although its core was centered in Roman occupied Judea and the Galilee (today's Israel), it's primary areas of growth were the far reaches of the Roman Empire, thanks primarily to the missionary efforts of Paul of Tarsus, along with others, who operated principally in Greece, Western Turkey, Syria, and, of course, Rome itself.
The early Christian movement was essentially a messianic Jewish sect, one of many at the time, and came about during a particularly tremulous period of simmering political and social tension as conquered peoples throughout the empire struggled under the yoke of Roman occupation.
Christianity, thus, incorporated fragments of other religions and philosophies; most notably Greco-Roman, which was dominate at the time, as were the teachings of the Jewish sage, Hillel. As such, it shares similarities with other sects like the cult of the Egyptian goddess Isis and the cult of Mithras, which was especially popular among the military class, as was the cult of the sun --- Sol Invictus, also associated with Mithras (collectively these were known as "mystery cults).
This new messianic sect, however, survived thanks in part to their wide dispersal around the empire. However, their survival was a mixed blessing. While they avoided the fate of Sadducees and Pharisees (and perhaps the Essenes), their refusal to acknowledge the divine sovereignty of the emperor, made them a "enemy of the state" for which they would pay a very high price.
They were often harassed or persecuted. They paid additional taxes, they constantly faced possible arrest and imprisonment, or were sold as slaves. Some emperors went so far as to include them as part of the "entertainment" for the Coliseum games, which literally included "feeding them to the lions" (and the tigers and bears...oh my!).
Emperor Nero was known to have them tied to poles, doused with oil and lit them on fire, thus serving as human candles during his nightly parties. Nevertheless, the sect continued to grow, albeit in secret. Meetings were held in secret in people's homes, forests, or in caves and catacombs among the dead.
Finally, in 312 AD, there came Constantine (later known as "Constantine the Great) and everything changed. Around October 28, 312, then General Constantine was engaged in a battle with Maxentius, the son of the dead Emperor Maximinus and heir apparent, over the control of the empire. It was another of Rome's infamous civil wars signifying a dying empire. The battle was at the Milvian Bridge (now Ponte Milvio), which spanned the Tiber River, and it would decide the fate of Rome.
The story that's come down from history is almost assuredly exaggerated, if not just a myth. It says that on the evening before the decisive battle, Constantine, turned his attention to the heavens and begged for divine support (or at least a sign). Accordingly, it was said that he saw a celestial cross in the sky and heard a voice whisper to him "in this sign you shall conquer".
Other stories have this as a dream and still others say that he was looking at the setting sun the day before the battle and saw a cross (this is often called a "sun halo" or a "sun dog"). Also, instead of hearing a voice saying "in this sign....", the voice said "through this sign you shall conquer". Did any of it really happen? Maybe. He did, no doubt, know that many of his officers and soldiers were secretly Christian and he desperately needed their support. Thus, it was said that he ordered a cross to be painted on all the shields, and if he won, he would convert to this new religion.
It's worth noting too that the cross was not then commonly associated with Jesus or Christianity, nor was it a particularly good omen since crucifixion was still in use. The more commonly accepted symbol for Christians was the fish (or ichthus). It should be mentioned that at this time Constantine wasn't a Christian. He was a follower of the Sol Invictus---the Invincible Sun.
But regardless of what Constantine saw or heard, he was victorious. Most of Maxentius' men fled. Maxentius drowned in the Tiber River, brought down by his heavy armor as he fell off his horse and into the swift river trying to flee with his troops. Assuming the sign as being responsible for his victory, all persecution of Christians stopped. Christianity now became the defacto official religion of Rome, which he made official with the signing of the Edict of Milan in 313, just one year after his victory.
In 314, Emperor Constantine summoned a council of key Christian leaders or "bishops" to Arles in Gaul (modern southern France). Technically, the meeting was to address the Donatists, a growing Christian sect based in Carthage (Rome's old enemy) and largely outside the control of Constantine. Their intent was to basically destroy this so-called "splinter" group before a irreparable schism could divide the emerging faith. However, the meeting was also to test Constantine's control over the bishops as well as establish precedent in dealing with other "heretical" sects (most notably the Arian and Gnostics).
A few years later, in 325, came the best known and most significant of the meetings, the Council of Nicaea. This meeting set about formally hammering out Christian doctrine, the organization of the church (which was loosely modeled on the Roman military), deciding on which biblical texts were "canon" and which weren't (and what parts of various texts were to be deleted or changed).
As an aside, Constantine declared the Sabbath would no longer be Friday/Saturday. The Sabbath would now be Sunday in honor of Sol Invictus and would applied to all religions per his decree on March 7, 321.As Christianity grew in popularity, it eventually replaced the other religions and Sunday became its own.
The Council of Nicaea also sought to clarify the nature of Jesus and establish whether he was divine, semi-divine, or simply an enlightened moral. They also dealt with other issues such as his birth (and thus Mary and her relationship vis-a-vis Jesus), his siblings, Joseph, God, and, of course, the various apostles, the role of women, the nature of sin, and so forth. The human Jesus was to be replaced by the immortal Christ as one of the delegates (an Arian) stated.
So what does all this have to do with Christmas? Just this. The Council of Nicaea, under the direction of Emperor Constantine, set forth the two central events for all Christians---Easter and Christmas. Easter, which symbolizes the belief in the resurrection of Jesus following his execution, as well as the nature and date of his birth. So, if you ever wanted to know when Christmas (or "Christ Mass") first started, this is it!
At the time of Nicaea, there were several differing Christian sects. Each had its own religious texts and traditions, which could vary widely. Some had certain books or texts than others didn't which included various stories about Jesus. For instance, some included stories of his birth. Some didn't. A few, but not all, mentioned his brothers and sisters. Some detailed more of his teachings. Others didn't, and so forth.
As an aside, the teaching of many of these "non-canonical" or unapproved texts would later be ordered to be discontinued while others were edited or considered as "apocryphal" and "pseudo-apocryphal" books. And yet other texts would be seized and destroyed. In fact, many of the smaller Gnostic sects would be burned as "heretics" along with their books. As a result, many of these sects hide or buried their sacred texts until, hopefully, safer times arrived.
Many of these early Christian sects which had a birth narrative that assumed Jesus was born in the Spring based on lines like "tending flocks in the field". Thus, March 28th was generally accepted as his birthday or at least, nativity. However, if Christianity was to be the "official" state religion, Constantine would still need to contend with the very popular pagan cults of Isis, Mithras, and Sol Invictus.
The Spring Solstice, which was celebrated a symbol of the nature's rebirth and fertility, fell conveniently in line to be the date of the resurrection. It was also close to the Jewish day of Passover, which was mentioned in the majority of various Christian texts pertaining to the crucifixion. Other events could (and eventually were) incorporated around these two central pillars of Christianity. Thus, Constantine brought the four main religions of the Rome Empire together, which he hoped would ease some of the mistrust and competition between them.
Note too that "Christmas" was, strictly speaking, a solemn day of worship. It simply meant "Christ Mass" or Mass of/for Christ". There was no tree or gift giving. The evergreen tree was incorporated from ancient Germanic pagan practices and first introduced in the 1500's. Legend holds that religious reformer (and one of my ancestors), Martin Luther, first placed candles on the trees after a walk in the forest where he saw stars peering through the limbs of snow covered evergreen trees.
The notion of gift giving dates back to ancient Celtic, Germanic, and Roman practices during the winter solstice celebrations. Typically these were inexpensive items such as combs, yarn, and flint. Expensive objects were actually frowned upon. It was believed that simple and practical were in keeping with the spirit of the season. By the late 300s, converted Christians had carried over the practice into their new found faith, which was supported by the gifts brought from the east by the three Magi.
