We must now examine more minutely the notice of Christ’s birth given us in this document. It runs as follows: I p. Chr. Cæsare et Paulo sat. XIII. Hoc cons. Dns. ihs. XPC natus est VIII. Kal. Jan. de ven. luna XV.[308] Which means, Christ was born during the consulship of C. Cæsar Augustus and L. Æmilius Paulus (754 U.C.), on the 25th December, which was a Friday, on the fifteenth day of the new moon.
This notice gives rise to several questions. First of all the Epact is not correct, as according to our tables it ought to be 11.[309] But this need not detain us, as two or three peculiarities of this kind are to be met with in this list of the consuls. The error concerning the day of the week is more important. To expose this error we need only give the dominical letters for the years in question:—
| 751 U.C., | Dom. let. | F | = | 25th Dec., | Wednesday. |
| 752 U.C., | ” | E | = | ” | Thursday. |
| 753 U.C., | ” | DG | = | ” | Saturday. |
| 754 U.C., | ” | B | = | ” | Sunday. |
The compiler of this chronology might have set down the birth of Christ in either 754 or 753 U.C. 754 is a possible year, although the 25th December 753 is more probable, yet in either case the day of the week would be wrong. In 752, the 25th December fell on Thursday, but since 753 was a leap year, the dominical letter advances two places, and Friday is passed over. At the same time, there has been a fairly constant tradition that the 25th of December fell on a Wednesday in the year of Christ’s birth. In any case, the notice that the 25th December fell, in this year, on a Friday is based on a mistaken reckoning. This notice, then, does not represent a tradition, but is merely the result of a calculation which unfortunately is incorrect. Consequently the whole interpolation is undeserving of credit. We now pass on to a second point.
While all writers before 354 fix the year of Christ’s birth by the year of the Emperor’s reign, here, for the first time, it is fixed by the year of the consuls. This is a marked departure from the original usage. The forty-first or forty-second year of Augustus correctly converted into a consular year would have run: Augusto XIII. et Silvano conss. or Lentulo et Messalino, which would also be the year 751 or 752 U.C., according as the year of the emperor is taken as “effektiv” or not, i.e. according as one places Christ’s birth in the first or second half of the year.[310]
Moreover, when the chronographer dates the year of Christ’s birth in the consulship of “Cæsar and Paulus” (754 U.C.), he anticipates the Dionysian era some two hundred years before Dionysius, and, further, when, in accordance with a very ancient tradition, he places the year of Christ’s death in the consulship of the “duo gemini” (29 A.D.), he thus only allows twenty-eight and a quarter years for Christ’s earthly life, while St Luke (iii. 23) speaks of Him as having wellnigh thirty full years. Whoever he may have been who inserted this notice under the consulship of Cæsar and Paulus in the chronology, he certainly made a mistake. He also stands alone in placing Christ’s birth in the year 754 U.C., for the writers and annalists who wrote at a later date, such as Sulpicius Severus, Orosius, Prosper, Hydatius, and even Cassiodorus, give other dates.
The anonymous compiler of this chronology differs also, both as to contents and form, from those who preceded him. While Irenæus, Clement of Alexandria, Tertullian, the pseudo-Cyprian, etc., fix the year of Christ’s birth by a year of the emperor, i.e. the forty-first or forty-second of Augustus, it is given in this document in the form of a consular year, and while the former give 751-752 U.C. as the year, the latter gives 754. All this creates great difficulty in accepting the evidence of the compiler.[311]
We must now deal with the day of the month given in the chronology, the 25th December, which, strictly speaking, alone is of importance in connection with the end we have in view, although it cannot well be separated from the previous question as to the year. It has recently been thought that Hippolytus afforded some very early evidence on this point, owing to a passage in his commentary on Daniel bearing upon the subject. However, this hope has proved deceptive,[312] since the passage in Hippolytus proves to be the addition of a much later hand; we are thus left with the chronology of 354 as the earliest evidence for placing the birth of Christ on the 25th December.
The result of our investigation of this compilation, made up of historical, chronological, and other materials, proves that the compiler, in collecting his materials in 354, added to the lists of consuls, which naturally he did not draw up himself, the notice that Christ was born under these particular consuls on the 25th December, because it was at that time the generally accepted date. It could only be widely accepted, when the festival of Christ’s birth had already been celebrated on this day, not recently but during a considerable period. It is very improbable that it had just been introduced by any one person in particular, such as the Bishop of Rome, for the first years of the reign of Liberius were very troubled and ill suited for the introduction of so important an innovation. Moreover, history shows that a thing like this cannot be done all at once by a stroke of the pen, or at the will of an individual, even though he be the Bishop of Rome, but is rather the outcome of a long period of preparation.