Now, if we go further back in the record (despite the fact that Christianity as we know it -- the one based on the Nicene creed -- only goes back to 325 CE), we will encounter a derogatory graffito scratched out during the government of Alexander Severus and the confusions promulgated by three writers known as "Church Fathers". First the Graffito:
A slight description of the graffito: "Alexamenos worships his god" (or Alexamenos, worship God!) is the inscribed message, apparently in response to a nearby graffito that proclaimed, "Alexamenos, always faithful." It has been reliably dated to just after the turn of the 3rd C. CE, during the reign of Alexander Severus.
Note that not only the god that Alex is worshipping is made fun of. The devotee's method of worship is also being sneered at: he is hailing his god with his left hand, which is about in line with the level of his mouth, which is also at the level of his god's penis. It appears that the tagger was thinking, Alexamenos is worshipping the virilia of his god. The god himself has a donkey's head, suggesting a very ample endowment. The god is also portrayed naked from the waist down, possibly implying that Alex is about to perform something more "worshipful" than a hailing from a distance. The Y next to the head of the god is very similar to metal defixiones (curse tablets) found in Rome, which had similar illustrations of a donkey's head next to a Y inscribed on one of the sides. Of course, this could mean that Alexamenos was not at all a Christian/Chrestian, but a devotee of Typhon-Seth.
Since not only Alexameno's god is portrayed in a derogatory manner, so is the manner in which the god has been crucified: on a T-shape cross, or tropaeum, complete with suppendaneum, instead of the usual pole equipped with a sedile/cornu.
And so we shall see if early "Church Fathers" confused the Roman crux (σταυρός) with the Roman tropaeum (τροπαῖον).
First at bat: Minucius Felix (Octavius, ch. 29).
These, and such as these infamous things [such as worshipping the virilia of their priest or the nature, i.e., genitals of their father -- see Octavius, ch. 9], we are not at liberty even to hear; it is even disgraceful with any more words to defend ourselves from such charges. For you pretend that those things are done by chaste and modest persons, which we should not believe to be done at all, unless you proved that they were true concerning yourselves.
For in that you attribute to our religion the worship of a criminal and his cross, you wander far from the neighbourhood of the truth, in thinking either that a criminal deserved, or that an earthly being was able, to be believed God. Miserable indeed is that man whose whole hope is dependent on mortal man, for all his help is put an end to with the extinction of the man....
Crosses (cruces), moreover, we neither worship nor wish for. You, indeed, who consecrate gods of wood, adore wooden crosses perhaps as parts of your gods. For your very standards, as well as your banners; and flags of your camp, what else are they but crosses glided and adorned? Your victorious trophies (tropaea) not only imitate the appearance of a simple cross (cruces simplicis),  but also that of a man affixed to it.
Crucis simplicis is the genitive of crux simplex. From the epigraphy, what Minucius Felix regarded as a crux simplex (the frame of a tropaeum) was not the same as that item (a plain pole) defined as such. And Minucius is the one who is accusing the Romans of crux-worship.
Next at bat, Tertullian.
You put Christians on crosses and stakes: what image is not formed from [white] clay in the first instance, set on cross and stake? The body of your god is first consecrated on the patibulum!Patibulum here could denote a T-shape gibbet, or rather, cross, by Tertullian's understanding. And he says when the body of their god (like a divine Caesar) is first dedicated, it is installed on a patibulum, or cross, that is, a tropaeum. Just like in this miniature Caesarean tropaeum, on display at the Berlin Museum in Charlottenburg, Germany, below:
Tertullian, Apologeticus 12:3
Note the ROMAN BREASTPLATE ARMOR on the tropaeum.
6 Then, if any of you think we render superstitious adoration to the cross (crux), in that adoration he is sharer with us. If you offer homage to a piece of wood at all, it matters little what it is like when the substance is the same: it is of no consequence the form, if you have the very body of the god. And yet how far does the Athenian Pallas differ from the stock of the cross, or the Pharian Ceres as she is put up uncarved to sale, a mere rough stake and piece of shapeless wood? 7 Every stake fixed in an upright position is a portion of the cross; we render our adoration, if you will have it so, to a god entire and complete (integrum et totum). We have shown before that your deities are derived from shapes modelled from the cross. But you also worship victories, for in your trophies (tropaea) the cross (crux) is the heart of the trophy (intestina tropaeorum). 8 The camp religion of the Romans is all through a worship of the standards, a setting the standards above all gods. Well, as those images decking out the standards are ornaments of crosses. All those hangings of your standards and banners are robes of crosses. I praise your zeal: you would not consecrate crosses unclothed and unadorned.Indeed, in the photo at the top, and the one just above, the "heart" of the tropaeum is indeed a cross. Now what for Tertullian is a crux integra et tota? Well he can explain.
Tertullian, Apologeticus 16:6-8
Any piece of wood planted upright in the ground is part of a cross and indeed the larger part of a cross. But we Christians are credited with an entire cross (tota crux) complete with a transverse beam (antenna) and [the well-known] projecting seat (ille sedilis excessu)
Tertullian, Ad Nationes 1.12.
Now at the link to the source above there is a note at the bottom of Ad Nationes I (1) chapter XII (.12) describing the projecting seat as a ledge, or bench. Other scholars, however, regard this piece to be a plank, beam, or peg: a sort of "phallus." So now we're not looking at a cross for the integra et tota crux (a crux uninjured and complete) executionary suspension device, but a T-pole apparently modeled after the Roman god Priapus.
No now we have a difference between the crux, commonly and almost universally to be regarded as a cross, and what actually was a cross: a tropaeum.
Third at bat, Saint Justin the Martyr.
But in no instance, not even in any of those called sons of Jupiter, did they imitate the being crucified; for it was not understood by them, all the things said of it having been put symbolically. And this, as the prophet foretold, is the greatest symbol of His power and role; as is also proved by the things which fall under our observation. For consider all the things in the world, whether without this form they could be administered or have any community. For the sea is not traversed except that trophy (τροπαίον) which is called a sail abide safe in the ship; and the earth is not ploughed without it: diggers and mechanics do not their work, except with tools which have this shape. And the human form differs from that of the irrational animals in nothing else than in its being erect and having the hands extended, and having on the face extending from the forehead what is called the nose, through which there is respiration for the living creature; and this shows no other form than that of the cross (σταυρός). And so it was said by the prophet, “The breath before our face is the Lord Christ.” And the power of this form is shown by your own symbols on what are called “vexilla” [banners] and trophies, with which all your state possessions are made, using these as the insignia of your power and government, even though you do so unwittingly. And with this form you consecrate the images of your emperors when they die, and you name them gods by inscriptions. Since, therefore, we have urged you both by reason and by an evident form, and to the utmost of our ability, we know that now we are blameless even though you disbelieve; for our part is done and finished.
Justin Martyr, I Apology 55
Justin Martyr notes that the "cross," or σταυρός, gives its form to the "trophy" (τροπαίον) that resides in a ship without which ships cannot sail, to the plough, and to the form where Romans dedicated wax images of their simultaneously deified emperors at their funerals (of course elsewhere [Dialogue with Trypho 91] he states that the actual execution device, the crux/σταυρός has the same shape that Tertullian credited it with, as we have seen). According to Franceso Carotta, this Roman Imperial tradition of consecrating emperors at their funerals with the form of a cross began with the funeral of the first Caesar, the divine Gaius Julius Caesar.
Below are various interpretations of how Julius Caesar's wax image was displayed on a tropaeum. The first two images are clearly erroneous, showing the body of Julius Caesar in imago with his arms down at the sides and behind the antenna like some common suspended criminal. It is more likely, given that the Senate had already proclaimed him a god, that Caesar's was image would be displayed with his arms extended, as a sign of victory; but on the other hand, extending the arms would have displayed each and every stab wound that Caesar received when he was assassinated with dagger-wielding men in the temporary House of the Senate in Pompey's Theatre. Thirdly, criminals suspended on cruces would not always have their arms down at their sides. Frequently, their arms would be extended along the device's transom, or patibulum (as well as a distinct beam or bar between two poles). So the crowd would have perceived Caesar's death as tantamount, or almost, to a Roman "crucifixion," that is, a suspension on some kind of T-pole (like our modern utility pole).
|Source: the History Channel (Divvs Ivlivs blog).|
|Source: Sitsim (Divvs Ivlivs blog).|
The above images depict what I believe to be an erroneous interpretation of the display of the wax image of Julius Caesar on a tropaeum.
|Source: Francesco Carotta, Jesus Was Caesar.|
This image shows a better, but still possibly erroneous interpretation, perhaps based on the mannekin-on-a-stick display of the crucified Christ in the Maxwell Ivories. Julius Caesar would surely have been stabbed in the back, yet the cross here blocks the view of the image's back.
|Source: Divvs Ivlivs blog.|
|Source: Gospel of Caesar (Steven Saylor's web page "Where Are The Euro Movies?")|