Most people assume that Jesus of Nazareth was born on 25 December 1 AD. Superficially speaking, this assumption makes a great deal of sense. After all, Christians today celebrate Jesus’s birth every year on December 25th and our modern Anno Domini dating system, which is ostensibly based on the year when Jesus was born, begins with the year 1 AD.
Unfortunately, things are never quite so simple. The truth is, we genuinely have very little idea when Jesus was born. There is no mention of the exact date of Jesus’s birth anywhere in any of the earliest surviving Christian writings and it was not until around the fourth century AD that December 25th was settled on as the day on which Christians would celebrate Jesus’s birth. Even the year of Jesus’s birth is uncertain; all we can say is that he was probably born sometime between c. 10 BC and c. 4 AD.
Probably not born on December 25th
Although Christians today celebrate the birth of Jesus on December 25th, the New Testament says absolutely nothing about the exact date when Jesus was born. If you read through all the gospels, the Book of Acts, all the epistles, and even the Book of Revelation, you will never find a single reference to the date of Jesus’s birth. December 25th is not mentioned anywhere in the Bible at all.
Indeed, if anything, the Gospel of Luke 2:8 seems to suggest that the author believed that Jesus was born during one of the warmer months of the year, since it describes shepherds spending the night outside in the fields with their flocks on the night when Jesus was born. In ancient Judaea, shepherds did not typically spend the nights outside during late December, since, even in Israel, it can get quite chilly at night during the winter and it is often rainy.
It is, of course, worth noting that modern historians generally reject both of the birth narratives in the Gospel of Matthew 1:18–2:23 and the Gospel of Luke 2:1–40 as fictional accounts invented by the gospel-writers or by their sources. (I intend to discuss this in much greater depth in an upcoming article.) Nonetheless, as far as when the Gospel of Luke portrays Jesus as having been born, late summer or early autumn is probably the best bet.
Even if we look past the canonical texts, the date of Jesus’s birth is never mentioned in any of the earliest surviving extra-canonical Christian sources either. Indeed, the Church Father Origenes of Alexandria (lived c. 184 – c. 253 AD) even seems to imply in his Homily on Leviticus that people should not celebrate their birthdays because, in the scriptures, only sinners celebrate their birthdays and never saints. It therefore seems that the earliest Christians were not particularly concerned with the question of the exact day on which Jesus was born.
ABOVE: The Adoration of the Shepherds, painted in 1622 by the Dutch Golden Age painter Gerard van Honthorst
A Christian alternative to Saturnalia?
It is difficult to say exactly how the tradition that Jesus was born on December 25th arose. By the time Christians started caring about when Jesus was born, they started proposing all sorts of different dates with all sorts of different arguments supporting them. There was not a single month out of the year that no Christians believed Jesus had been born in. Somehow, out of all these various proposed dates, December 25th eventually caught on and became accepted as the canonical date of Jesus’s birth.
One popular explanation for why Christians might have chosen to celebrate Jesus’s birth on December 25th is that they may have been trying to create a Christian alternative to the traditional Roman holiday of Saturnalia. There are several problems with this idea, though. First of all, by the fourth century AD, Saturnalia was a largely secular holiday and many Christians actually do not seem to have had much of a problem with it.
Another problem with this idea is that Saturnalia actually lasted from December 17th through December 23rd, meaning the holiday would have already been officially over by the time Christians would have been celebrating Christmas. If Christians had been intentionally trying to create Christmas as a Christian alternative to Saturnalia, you would think they would have put it on the exact same day so that people couldn’t celebrate both Saturnalia and Christmas.
Finally, we have very good evidence that many people continued to celebrate Saturnalia alongside Christmas long after the Roman Empire’s official conversion to Christianity. Both Christmas and Saturnalia are listed as holidays on the Chronograph of 354, a Roman calendar for the year 354 AD.
Furthermore, one of our most details sources on the holiday of Saturnalia is the treatise Saturnalia, which was written by the Roman antiquarian Macrobius Ambrosius Theodosius sometime around 400 AD, after public veneration of the traditional Greco-Roman deities was officially outlawed. In other words, if Christians were trying to suppress the holiday of Saturnalia by replacing it with Christmas, then, in the short-term at least, it seems they were not very successful.
ABOVE: Photograph of the front page of an early printed edition of Macrobius’s treatise Saturnalia, printed in 1560. Macrobius wrote his Saturnalia sometime around 400 AD—after public veneration of the traditional deities was officially outlawed.
A holiday for Sol Invictus?
There is a widespread belief that December 25th was the date of an important pre-Christian religious festival in honor of the birth of a non-Christian deity. This is possible, but the evidence to support this conclusion is not very strong. Of all the non-Christian deities that are so routinely claimed to have been born on December 25th, the only one who is actually documented to have been believed by anyone in antiquity to have been born on December 25th is Sol Invictus, whose name means “the Unconquered Sun.”
The cult of Sol Invictus was introduced to Rome by the Roman emperor Elagabalus (ruled 218 – 222 AD), whom I wrote about in this article I published in November 2019. Sol Invictus remained a prominent deity in Rome for the remaining portion of Rome’s pagan history. Nonetheless, the evidence for Christians having appropriated a pagan holiday honor of the birth of Sol Invictus as a Christian holiday in honor of the birth of Jesus is extremely ambiguous to say the least.
The problem is that there is only one surviving source that records Sol Invictus’s birth being celebrated on December 25th at all and that particular source happens to be extremely late. The only source that records Sol Invictus’s birth being celebrated on December 25th is the Chronograph of 354, which dates to a time several decades after Constantine I’s legalization of Christianity. At the time when the Chronograph of 354 was written, Christianity was rapidly becoming the dominant religion of the Roman Empire. Indeed, the author of the Chronograph of 354—a certain man by the name of Furius Dionysius Filocalus—is known to have been a Christian himself.
In fact, it so happens that, in addition to mentioning that the birth of Sol Invictus was celebrated on December 25th, the Chronograph of 354 also mentions that Jesus’s birth was celebrated on December 25th. The two holidays are simply listed right alongside each other. We have no earlier sources whatsoever that make any reference to December 25th being celebrated as the birthdate of Sol Invictus.
ABOVE: Third-century AD Roman silver plate depicting the sun god Sol Invictus, whose birthday, according to the Chronograph of 354, was celebrated on December 25th
Who copied whom? Did anyone?
Although many people have made a big deal about Christians copying traditions from pagans, the copying actually went both ways; Christians copied off pagans and pagans copied off Christians. The question here is: when it comes to celebrating the birth of a god on December 25th, who copied off whom? Did the Christians copy the cult of Sol Invictus or did the cult of Sol Invictus copy the Christians?
Since the Chronograph of 354 mentions the births of both Jesus and Sol Invictus being celebrated on December 25th, we have no way of knowing if December 25th was originally a festival of Sol Invictus and Christians turned it into a festival for Jesus or if Christians were celebrating the birth of Jesus on December 25th first and then the cult of Sol Invictus came along and decided to start celebrating the birth of their god on the same day.
Furthermore, we must also consider the possibility that Christmas and the birthdate of Sol Invictus may have fallen on the same day by coincidence without either group deliberately copying the other. Although December 25th was not actually the date of the winter solstice in ancient Rome, many ancient Roman writers reference it as being the winter solstice. It is possible that Christians and members of the cult of Sol Invictus independently chose December 25th as the birthdate of their respective deities on account of this fact.
Although hypotheses of this subject are plentiful, the most likely explanation for how the notion that Jesus was born on December 25th arose is that it arose from a belief that was popular in late antiquity that great men died on the same date they were conceived. This belief seems to have led some early Christians to conclude that the Annunciation of the Virgin occurred on March 25th, which was apparently believed by some people to have also been the date of the crucifixion. Then, because a pregnancy lasts for nine months, they concluded Jesus must have been born on December 25, because December 25th is exactly nine months after March 25th.
Since this explanation for why Christians might have independently chosen December 25th as the day to celebrate Jesus’s birth exists, I am inclined to think that Christians probably chose December 25th as the day to celebrate the birth of Jesus on their own without being directly influenced by the cult of Sol Invictus. It is possible that the cult of Sol Invictus may have chosen December 25th to celebrate the birth of their deity in imitation of Christians, but I am inclined to think that they probably selected this date independently also because they considered it the date of the winter solstice.
If this is the case, the fact that the births of Jesus and Sol Invictus were celebrated on the same day may just be a coincidence. In any case, we have no good reason to think that Jesus was actually born on December 25th. There is nothing in any of the gospels about Jesus having been born on December 25th and, furthermore, the decision to celebrate December 25th as Jesus’s birthday did not occur until centuries after Jesus’s death.
ABOVE: Illustration for the month of December from the Berberini Manuscript of the Chronograph of 354
Origins of the Anno Domini dating system
Now that we have talked about what day Jesus was born on, let’s talk about which year he was born in. The system of dating we use today is the Anno Domini system, which begins with the year 1 AD, the year in which Jesus was supposedly born. Anno Domini means “in the Year of the Lord” in Latin. It is abbreviated from the longer earlier phrase “anno Domini nostri Jesu Christi,” which is Latin for “in the year of our Lord Jesus Christ.”
This dating system was developed in around 525 AD by a Scythian monk named Dionysius Exiguus (lived c. 470 – c. 544 AD), who is sometimes known in English as “Dennis the Short.” Prior to Dionysius Exiguus, some Christians used a different dating system known as the Anno Martyrum or Anno Diocletiani system, which dated events from 20 November 284 AD, the year when Diocletian became the emperor of the Roman Empire.
The reason why some Christians used this date was because Diocletian was a notorious persecutor of Christians who put many of them to death and Christians regarded those who died for their faith as heroic martyrs. Thus, they wanted to commemorate the brave and heroic sacrifice of these men and women who had given their lives to the cause.
Many Christians, however, were uncomfortable with the Anno Martyrum system because it dated events from the beginning of the reign of a man who was known as a notorious persecutor of Christians. Many people believed that Diocletian did not deserve the honor of having the new era begin with his reign. Thus, Dionysius Exiguus proposed the Anno Domini system as a replacement for the Anno Martyrum system. He proposed that, instead of dating events from 284 AD, people should date events from the birth of Christ, which he concluded had happened in 1 AD.
ABOVE: Roman marble head of the emperor Diocletian, the beginning of whose reign in 284 AD marked the beginning of the Anno Martyrum dating system, which was used by some Christians prior to the creation of the modern Anno Domini system
Evidence for Jesus having been born around 1 BC or 1 AD
The Gospel of Luke 3:1–2 dates the beginning of Jesus’s ministry to “the fifteenth year of the reign of Emperor Tiberius, when Pontius Pilate was governor of Judea, and Herod was ruler of Galilee, and his brother Philip ruler of the region of Ituraea and Trachonitis, and Lysanias ruler of Abilene, during the high priesthood of Annas and Caiaphas.” The emperor Tiberius began his reign on 18 September 14 AD. That means the “fifteenth year of the reign of Tiberius is the year from 18 September 29 AD to 18 September 30 AD.
Although none of the other canonical gospels give such a precise date for the beginning of Jesus’s ministry, all four canonical gospels do agree that, when Jesus was put on trial, Pontius Pilatus was the governor of Judaea and Caiaphas was the High Priest of the Temple in Jerusalem. In other words, the date that the Gospel of Luke gives for the beginning of Jesus’s public ministry is compatible with the details found in the other gospels.
Later on, the Gospel of Luke 3:23 states, “Jesus was about thirty years old when he began his work.” If Jesus was “about thirty” when he began his ministry in either 29 or 30 AD, then, logically, he must have been born sometime around 1 BC or 1 AD, give or take a few years. Dionysius Exiguus settled on 1 AD as the year of Jesus’s birth and his date has stuck ever since.
ABOVE: Roman marble portrait bust of the emperor Tiberius from the Carlsburg Glyptothek in Copenhagen. According to the Gospel of Luke, Jesus began his public ministry in “the fifteenth year of the reign of Emperor Tiberius” (i.e. 29/30 AD) when he was “about thirty years old.”
“In the reign of King Herod”
There are, however, statements about when Jesus was born in the gospels that are directly incompatible with Dionysius Exiguus’s conclusion of him having been born in 1 AD. Most significantly, the Gospel and Matthew 2:1 and the Gospel of Luke 1 independently record that Jesus was born during the reign of King Herod the Great. We know with a great deal of certainty from the writings of the Jewish historian Josephus (lived c. 37 – c. 100 AD) that King Herod the Great died in 4 BC.
Josephus records in his Antiquities of the Jews 17.6.4 that King Herod died shortly after a lunar eclipse preceding the Passover. Astronomical events such as this one can be dated precisely because scientists know the exact mathematical formulas for calculating the movements of astronomical bodies. Astronomers can therefore turn back the clock using mathematics to reverse-predict exactly when astronomical events in the past happened. Using this very precise astronomical dating, we know that the eclipse preceding Herod the Great’s death happened on exactly 13 March 4 BC, twenty-nine days before the Passover.
This means that, assuming that the gospels’ testimony that he was born during the reign of Herod the Great is correct, 4 BC is the latest Jesus could have been born. If we assume that Jesus was indeed born during the reign of Herod the Great as the gospels claim he was, then the modern Anno Domini dating system is clearly off by at least four years.
ABOVE: Modern fictional portrait intended to represent King Herod the Great. No one knows what Herod really looked like, but, according to the gospels at least, Jesus was born towards the end of his reign.
During the census of Quirinius?
If this were all the information we had about when Jesus was born, we might reasonably conclude that Jesus was born sometime between c. 6 BC and c. 4 BC, towards the very end of the reign of King Herod the Great. This would make Jesus between thirty-three and thirty-five years old at the time when he began his ministry, which could reasonably be described as “about thirty.”
Unfortunately, things are not quite so simple. We have further statements from the Gospel of Luke that blatantly contradict the statements found in the Gospel of Matthew and the Gospel of Luke about Jesus having been born during the reign of King Herod the Great. The Gospel of Luke 2:1–5 claims that Jesus was born during the census of Quirinius. Here is the passage, as translated in the NRSV:
“In those days a decree went out from Emperor Augustus that all the world should be registered. This was the first registration and was taken while Quirinius was governor of Syria. All went to their own towns to be registered. Joseph also went from the town of Nazareth in Galilee to Judea, to the city of David called Bethlehem, because he was descended from the house and family of David. He went to be registered with Mary, to whom he was engaged and who was expecting a child.”
The census of Quirinius that the author of the Gospel of Luke specifically mentions here is a well-attested historical event described by Josephus in his Antiquities of the Jews. The problem is that the census occurred in 6 AD—a full nine years after the death of King Herod the Great in 4 BC. Obviously, since the census of Quirinius took place in 6 AD and Herod the Great died in 4 BC, Jesus could not have possibly been born during the reign of Herod the Great and during the census of Quirinius. This is a blatant and undeniable contradiction in the Gospel of Luke’s narrative.
Evangelical apologists have tried to explain away this contradiction by claiming that Quirinius must have had an earlier, unrecorded term as governor of Syria about a decade before he is recorded to have become governor of Syria. They furthermore claim that Quirinius must have conducted an earlier census during this earlier, imaginary previous term as governor. The problem is that we have absolutely no evidence of any of this. We only have record of Quirinius having served as governor of Syria once and we only have record of one census conducted during Quirinius’s term as governor, which is that one that was conducted in 6 AD.
ABOVE: The Adoration of the Shepherds, painted between 1500 and 1510 by the Italian Renaissance painter Georgione
Now, there are many other serious problems with the Gospel of Luke’s account of the census, which I intend to discuss in an upcoming article about how the nativity stories in the Gospel of Matthew and Gospel of Luke are both probably complete fiction. Here, though, I will limit my discussion to the fact that the Gospel of Luke’s claim that people were required to return to the place of their birth to register for the census is absolutely insane.
Outside of the Gospel of Luke, we have no record of any census conducted in antiquity having ever required people to return to their place of birth. The very idea of this sort of rule is never mentioned in any Roman records. Furthermore, there is no logical reason why anyone would have made such a requirement, since people could easily have been counted where they were. Finally, if anyone had tried to conduct a census of the Roman Empire in which everyone was required to return to their place of birth to register, it would have thrown the Empire into a state of mass chaos.
During the time of the Roman Empire, it was relatively common for people to live in a completely different part of the empire from where they were born. The Roman roads and Roman control of the Mediterranean Sea made transportation much easier than it had been in previous eras. As a direct result of this, there were people from Syria living in Spain, people from Egypt living in France, and so on.
If, at any point, everyone in the Roman Empire had been ordered to travel all the way back to their place of birth, it would have resulted in universal chaos, confusion, and catastrophe. Within the context of Luke’s narrative, it is abundantly clear that the rule about everyone having to return to the place of their birth to be counted for the census is nothing more than an excuse to explain how Jesus could have been born in Bethlehem when everyone knew he and his family all came from Nazareth. The Gospel of Matthew offers a completely different excuse that Jesus’s family originally lived in Bethlehem and only later settled in Nazareth after they returned from a sojourn in Egypt.
ABOVE: Byzantine mosaic dating to c. 1315 AD or thereabouts depicting Joseph and Mary registering for the census of Quirinius, as described in the Gospel of Luke
Jesus was “not yet fifty years old”?
Oh, but, if you thought all these contradictions were confusing enough, you were wrong, because there is still one more confusing wrinkle to add to this story! In the Gospel of John 8:39–59, Jesus is portrayed as getting into an argument with a group over Jews over the subject of Abraham. In the Gospel of John 8:57, the Jews are portrayed as saying to Jesus, “You are not yet fifty years old, and have you seen Abraham?”
It would probably be heavy-handed to interpret this passage to mean that Jesus was in his late forties at the time when he was conducting his public ministry, since “not yet fifty years old” does not necessarily mean “nearly fifty years old.” Nonetheless, this passage at least leaves open the possibility that the author the Gospel of John may have believed that Jesus was significantly older than the author of the Gospel of Luke describes him as being at the time of the start of his ministry.
If we interpret this comment from the Gospel of John to mean that Jesus was somewhere in his late forties at the time of his public ministry—which, again, is a bit of a problematic interpretation—that could mean that, according to the Gospel of John, Jesus may have been born as early as, say, around 18 BC.
Conclusion
The historical Jesus was probably not born on December 25th or in the year 1 AD. The truth is, no one knows exactly when he was born. The canonical gospels are so full of vagaries and contradictions that we are really reduced to pure guesswork when it comes to the date of Jesus’s birth.
If we assume that Jesus was either in his late twenties or in his thirties during the time of his public ministry, then he must have been born at some point roughly between c. 10 BC and c. 4 AD. This is probably the best estimate we can realistically make for when Jesus was born. Nonetheless, we cannot completely rule out the possibility that he may have been as old as his late forties, in which case he may have been born in the early 10s BC.
It is worth noting that this same problem actually applies to most historical figures from ancient times. People in antiquity did not keep birth certificates, so the exact date of when a person who lived in antiquity was born is often ambiguous. For instance, we only have extremely rough impressions of when people like Pythagoras, Perikles, Socrates, and Plato were born.
Estimates for when Plato was born range from c. 428 BC to c. 423 BC. Estimates for when Pythagoras was born vary even more widely, since his life is less well-documented. Really, Pythagoras could have been born anytime between c. 580 BC and c. 560 BC. In other words, the problem of not knowing exactly when an ancient historical figure was born is not a problem unique to Jesus by any means. In fact, we rarely ever know the exact date when a person who lived in ancient times was born.
