On 'the Twelfth Year of Tiberius Caesar' as the Original Gospel Account [Part One]

After all, or, if you like, before all, since you (Marcion) have said that he has a creation of his own, and his own world, and his own sky; we shall see, indeed, about that third heaven, when we come to discuss even your own apostle. Meanwhile, whatever is the (created) substance, it ought at any rate to have made its appearance in company with its own god. But now, how happens it that the Lord has been revealed since the twelfth year of Tiberius Cæsar, while no creation of His at all has been discovered up to the fifteenth of the Emperor Severus (= the time Tertullian was presumably writing); although, as being more excellent than the paltry works of the Creator, it should certainly have ceased to conceal itself, when its lord and author no longer lies hid?

I ask, therefore, if it was unable to manifest itself in this world, how did its Lord appear in this world? If this world received its Lord, why was it not able to receive the created substance, unless perchance it was greater than its Lord? But now there arises a question about place, having reference both to the world above and to the God thereof. For, behold, if he has his own world beneath him, above the Creator, he has certainly fixed it in a position, the space of which was empty between his own feet and the Creator's head. Therefore God both Himself occupied local space, and caused the world to occupy local space; and this local space, too, will be greater than God and the world together. For in no case is that which contains not greater than that which is contained. And indeed we must look well to it that no small patches be left here and there vacant, in which some third god also may be able with a world of his own to foist himself in. Now, begin to reckon up your gods. There will be local space for a god, not only as being greater than God, but as being also unbegotten and unmade, and therefore eternal, and equal to God, in which God has ever been. Then, inasmuch as He too has fabricated a world out of some underlying material which is unbegotten, and unmade, and contemporaneous with God, just as Marcion holds of the Creator, you reduce this likewise to the dignity of that local space which has enclosed two gods, both God and matter.

For matter also is a god according to the rule of Deity, being (to be sure) unbegotten, and unmade, and eternal. If, however, it was out of nothing that he made his world, this also (our heretic) will be obliged to predicate of the Creator, to whom he subordinates matter in the substance of the world. But it will be only right that he too should have made his world out of matter, because the same process occurred to him as God which lay before the Creator as equally God. And thus you may, if you please, reckon up so far, three gods as Marcion's—the Maker, local space, and matter. Furthermore, he in like manner makes the Creator a god in local space, which is itself to be appraised on a precisely identical scale of dignity; and to Him as its lord he subordinates matter, which is notwithstanding unbegotten, and unmade, and by reason hereof eternal. With this matter he further associates evil, an unbegotten principle with an unbegotten object, an unmade with an unmade, and an eternal with an eternal; so here he makes a fourth God. Accordingly you have three substances of Deity in the higher instances, and in the lower ones four. When to these are added their Christs— the one which appeared in the time of Tiberius, the other which is promised by the Creator— Marcion suffers a manifest wrong from those persons who assume that he holds two gods, whereas he implies no less than nine, though he knows it not.[Against Marcion 1.15]

Tertullian is clearly attacking the Marcionite understanding of Jesus so we may suppose that this was probably the original Marcionite gospel reading.  Yet there are some more points we have to make.  The first being that our familiar 'fifteenth year of Tiberius' follows a few chapters later, but it is obviously secondary because it is set in a chronology which necessarily assumes a much earlier date for Jesus's appearance on earth:

For the time it must suffice to follow up bur present argument so far as to prove, and that in few words, that Christ Jesus is the representative of no other god than the Creator. In the fifteenth year of Tiberius Caesar Christ Jesus vouchsafed to glide down from heaven, a salutary spirit. In what year of the elder Antoninus the pestilential breeze of Marcion's salvation, whose opinion this was, breathed out from his own Pontus, I have forborne to inquire. But of this I am sure, that he is an Antoninian heretic, impious under Pius. Now from Tiberius to Antoninus there are a matter of a hundred and fifteen and a half years and half a month. This length of time do they posit between Christ and Marcion. Since therefore it was under Antoninus that, as I have proved, Marcion first brought this god on the scene, at once, if you are in your senses, the fact is clear. [ibid 1:19]

The point here is that scholars like to pretend that Tertullian is telling us when Marcion appeared on the scene.  The reality is that he is actually saying - "I don't know when Marcion actually first appeared, but since I know it was in the Antonine age, let's give a date of 138 CE and count backwards."  The Edessan Chronicle seemed to have done the very same thing.  But here is the problem - Tertullian is supporting a date of 23 CE for the crucifixion!