Before we can hope to answer the question of what the Star of Bethlehem was, we must first find out when the events associated with it related by Matthew and Luke actually happen: when was Jesus born, or phrased differently, when was the first Christmas?

This is actually one of the most difficult elements of the Nativity story to tie down with certainty. We have a series of clues – what is often pompously called contextual evidence by biblical scholars:

1. Herod the Great was king.
2. Caesar Augustus was emperor.
3. Quirinius was Governor of Syria.
4. There was a global census.
5. Shepherds were watching their flocks by night.

Points (1) to (4) look restrictive but, in reality, just sow confusion. Here are the dates that they indicate:

• Herod the Great was King between 37 BC and 4 BC.
• Augustus was emperor between 27 BC and 14 AD.
• Quirinius was Governor of Syria in 6 and 7 AD.
• There were global censuses in 28 BC, 8 BC and 14 AD.

We can satisfy conditions (1), (2) and (4) in 28 or in 8 BC. We can satisfy conditions (2) and (3) in 6 and 7 AD. We can satisfy conditions (2) and (4) in 14 AD. But there is no way to satisfy all four conditions at the same time.

Both Herod and Augustus had extremely long reigns by the standards of the time. Augustus was declared emperor early in 27 BC, ending the Republic, at which point Herod had already been on the throne for several years.

Josephus dates the battle of Actium as having taken place in the seventh year of Herod’s reign (The Wars of the Jews: Book 1, Chapter 19:3). Josephus also goes into great detail about the symptoms that Herod showed before his death and the murderous splurge that he carried out in his last week of life, putting two of his sons to death for conspiring against him:

So Herod, having survived the slaughter of his son five days, died, having reigned thirty-four years since he had caused Antigonus to be slain, and obtained his kingdom; but thirty-seven years since he had been made king by the Romans (The Wars of the Jews, Book 1, Chapter 33:8).

We know that the Roman Senate voted to make Herod king of Judea in 41 BC, so Josephus indicates that he died in 4 BC.

The Census

The census reference, particularly juxtaposed with Quirinius, has caused endless confusion. It is—or at least has been—almost universally agreed that the census referred to by Luke is the one that took place in 8 BC. The decree for it was found in Ankara (Turkey) inscribed on the Monumentum Ancyranum.  There are two problems with this theory:

• It did not apply to Joseph.
• Quirinus was not Governor of Syria until 13 years later.

The census did state that it applied to the whole world, but that meant to the Roman world, and therefore to Roman citizens. Joseph was a Jew and Judea was a Protectorate of Rome; he was not a Roman citizen. In fact, the results, the Res Gestae, show that just 4,063,000 people were counted, and this tells that there were this number of Roman citizens in the Empire in 8 BC. The entire population of the Empire is known to have been 45.5 million at the death of Augustus. This means that fewer than 10% of the population was included in the 8 BC census.

We also know that Quirinius did organise a census for Augustus, because we have physical evidence in this tablet:

Even my largely forgotten Latin can make out the words “Divi Aug” (Divine Augustus), “Quirinio Legato Cesaeris Syriae” and, even more importantly “Quirini censum” and work out that they imply that Quirinus organised a census for Augustus in the Province of Syria. Was this the census Luke refers to?

The Greek word used by Luke to describe it is απογραφη – apografe. This word can be translated as both a call to census, or a call to register, in the sense of registering at the Town Hall. Why Joseph, as a citizen of a Roman Protectorate but not a Roman citizen, would need to respond to Augustus’s call to census is inexplicable. But if this was a local register for tax purposes or to count availability for military service, why would Joseph need to travel to his birthplace?

Here again Josephus appears to have the answers. In The Antiquities of the Jews, XVII, 1:1 he talks of Luke’s census:

Now Cyrenius, a Roman senator… came at this time into Syria, with a few others, being sent by Caesar to be a judge of that nation, and to take an account of their substance… the taxings, which were made in the thirty-seventh year of Caesar’s victory over Antony at Actium… [It was this imposition of Roman taxes when Judea was absorbed into the Roman Empire that led to the first Jewish revolt.]

Josephus dates this tax-levying campaign very precisely as having happened in 6 AD and as having been tied-in with the disposal of the wealth of Herod’s deposed successor; the self-same census as described in the tablet reproduced above. And thus, it looks as though Luke confused the 8 BC Empire-wide census with the local 6 AD census in the province of Syria.

The eclipse

Josephus also relates a key event in our investigation of the circumstances surrounding the birth of Jesus, which took place just before Herod’s final decline and death:

Now it happened, that during the time of the high priesthood of this Matthias, there was another person made high priest for a single day, that very day which the Jews observed as a fast. The occasion was this: This Matthias the high priest, on the night before that day when the fast was to be celebrated, seemed, in a dream, to have conversation with his wife; and because he could not officiate himself on that account, Joseph, the son of Ellemus, his kinsman, assisted him in that sacred office. But Herod deprived this Matthias of the high priesthood, and burnt the other Matthias, who had raised the sedition, with his companions, alive. And that very night there was an eclipse of the moon. (The Antiquities of the Jews; Book XVII, Chapter 6:4)

In case you didn’t get that (it’s not so obvious), this passage implies that there was an eclipse of the Moon visible from Jericho just prior to Passover, within a month of the death of Herod.

Passover is determined from the date of 15 Nisan in the Jewish calendar (April 1^st in 6 BC, March 21^st in 5 BC, April 10^th in 4 BC, March 29^th in 3 BC, etc.) And so, was there an eclipse of the Moon around this time?

• Between January 1^st 10 BC and December 31^st 1 AD there were 29 lunar eclipses.
• But, 10 were not visible from Jericho at any stage.
• Of the remaining 19, 10 were penumbral eclipses that were very unlikely to have been detected visually.
• The 9 eclipses visible from Jericho were:

Date	Year	Type
10 December	10  BC	Partial, 60%
3 June	9  BC	Total
28 November	9  BC	Total
18 November	8  BC	Partial, 43%
23 March	5  BC	Total
15 September	5  BC	Total
13 March	4  BC	Partial, 35%
9 January	1  BC	Total
29 December	1  BC	Partial, 63%

Of this list, only the eclipses of 5 BC and 4 BC occurred within a month of Passover.
However, the 5 BC eclipse happened immediately after the date of 15 Nisan, so can be excluded. This leaves only the 4 BC March 13^th eclipse of the Moon until 6 AD as a good candidate for the eclipse referred to by Josephus.  It would not have been a particularly spectacular eclipse. People would have observed something similar this photograph of the March 2003 lunar eclipse, as seen from the Catalan Region of Spain.

The eclipse reference suggests that Herod died in late March 4 BC. This is consistent with the dating that he had died 37 years after the Senate vote, and nine years before Quirinius’s census.

The date of the Nativity

We now meet a Scythian monk who has been, in my view, shamefully slandered for four centuries. This monk, Dionisius Exiguus, was asked in 525 AD to prepare a new Easter calendar for the church.

For several centuries the date of Easter threatened the church with schism. Initially it was calculated from the date of 15 Nisan, but different currents within the church celebrated different dates—some keeping strictly to 15 Nisan, others insisting that it could only be on a Sunday. Also, as Passover started at sunset the previous day, sometimes Easter fell—unacceptably to the church—before the Spring Equinox. This led to heated debate about “ἐπὶ ταῖς τοῦ σωτηρίου Πάσχα ἑορταῖς” (epi tais tou sooteriou Pascha heortais – the celebration of the Pascual Full Moon that gave life). It was decided at the Council of Nicea, in 325 AD, to celebrate Easter on the Sunday after the first Full Moon after the Equinox.

Sounds simple? Not at all. This was the Ecclesiastic Full Moon, defined as being exactly fifteen days after the previous New Moon. As the Moon’s orbit is quite elliptical, it traverses the more distant part much more slowly than when it is closest: this means that the interval from New Moon to Full Moon can be as little as thirteen days in reality and the Ecclesiastic Full Moon can be as much as two days after the real one. The so-called Saros Cycle of 19 years – 235 lunar months – was used to calculate the date of future Pascual Full Moons as, 235 lunar months after a given Full Moon, the Full Moon would again fall on the same date. Then, a more exact cycle of 95 years in the dates of Full Moons  – 1176 lunar months – was discovered. Each church used its own method of calculation and published its own tables of the future dates of Easter in happy contradiction with one another.

Dionisius’s task was to prepare a new and definitive ninety-five year Easter calendar. This, he published as Liber de Paschate – the Pascual Book. He is, however, better remembered for two things that he added to the book:

1. He changed the meaning of “AD” from being Anno Diocleciano—dates reckoned from the Era of Martyrs under Emperor Diocletian—to Anni Domini Nostri Jesu Cristo, now abbreviated “Anno Domini”, and
2. He stated that his book was published 525 years after the Nativity, which he defined as having been on December 25^th, usually assumed to be in 1 AD, but never specified.

Why was the Nativity not set in the year 0? Quite simply because Roman numerals have no symbol for “0”. Hence, he was obliged to jump straight from 1 BC to 1 AD. And so, rather illogically, in the standard definition, the Nativity happened at the end of the first year AFTER Christ.

What was the nominal Year 0? Eusebius of Caesarea (c. 263 – 339), wrote that Jesus was born in the 28^th year of reign of Augustus, while the Alexandrian church used the 23^rd year of Augustus’s reign: a five year difference that has unjustly gone down in history as “Dionysisus’s Five Year Error”.

And the consequence? 27 years after the start of Augustus’s reign is 1 AD. 22 years after would be 5 BC. How can both be right? Remember that we have three ways of dating the start of Augustus’s reign: from the battle of Actium in 31 BC that made him de facto emperor, or even his election as Consul in 33 BC that established him as the highest power in Rome and the Senate vote in 27 BC that formalised it. If Eusebius used the first definition and the Alexandrians, the latter, we get a date in 4 or 5 BC: conveniently before the March 4 BC death of King Herod and confirmation of Matthew’s chronology.

Other limits on the date of the Nativity

Josephus was not the only Roman historian to write of the life and works of Jesus. Tacitus also talks of him, writing in Annals, 15:44 that Pilate was responsible for condemning Jesus to death during the reign of Tiberius. It is generally accepted that Jesus died at 33 years of age. Tiberius reigned from 14 AD to 37 AD and Pontius Pilate was the fifth prefect appointed to the Roman province of Judea, arriving in 26 BC. If the Nativity happened before 8 BC, Jesus would have died before his prefecture. This simply does not support those who suggest that the Nativity may have happened as early as 10 BC.

In conclusion, therefore, the best estimate that we can make from the available—and contradictory—evidence is that the Jesus was born after 8 BC and before March 4 BC. The catholic church has accepted that the basis of the western calendar is wrong, given that Pope Ratizinger wrote in his book “The Infancy of Christ” in 2012 that the Nativity occurred before 4 BC.

If we want to find a Star of Bethlehem, we must then focus on events and astronomical phenomena that would have occurred between 8 and 4 BC. In the next post we will look at the question of whether or not the correct date for Christmas is December.