The iconic image of the Christian cross tends to feature a central vertical beam transected by a perpendicular beam about a third of the way down. This version of the cross is visible everywhere from emoji (which include both the two-beam Latin cross and the Orthodox cross, also known as the Suppedaneum cross, which has another bar near the bottom) to roadside memorials and, of course, church steeples.

But the actual crosses Romans used for executions probably took a different shape. The Greek and Latin words for “cross” — “stauros” and “crux” — do not necessarily describe what most people imagine as a cross. They refer to an upright stake upon which the condemned could be bound with hands above their heads. Most historians surmise that Jesus’ cross was more likely to have been T-shaped, with the vertical element notched to allow executioners to tie the victim to the crossbeam, then raise it and set it securely into the top. The Tau cross, named for its resemblance to the Greek letter, has been adopted over time by various Christian orders and sects, and it probably bears a stronger resemblance to the object upon which Jesus died on than those crosses more commonly depicted in Christian art.

Nearly every depiction of Jesus’ crucifixion — including masterpieces such as Sandro Botticelli’s “Mystic Crucifixion” and Diego Velázquez’s “Christ Crucified” — shows Him attached to the cross by nails through his palms and his feet.

The New Testament Gospels do not, however, directly say that Jesus was nailed to the cross. In fact, the only reference to such nails in the Gospels comes from the book of John and the story of doubting Thomas, who asks to see the marks of the nails in Jesus’ hands to confirm that he is really encountering the resurrected Christ (John 20:25). The tradition that Jesus was nailed to the cross may also derive from the passage in some translations of Psalm 21:16 that says, “They pierce my hands and feet.”

The Gospel of John states that Jesus bore the cross by himself (John 19:17) to a hill called Golgotha, while the Gospels of Matthew, Mark and Luke claim that authorities compelled a passerby, Simon of Cyrene, to carry the cross for Him, presumably because the flogging He had received had left Him too weak to carry it. In either case, most depictions in Christian art (including renditions by Michelangelo, El Greco and Titian) show either man carrying a large, wooden cross with both a vertical and a horizontal beam.

Yet Romans generally had the upright beam already set up at the place of execution. To the extent that the condemned carried their own crosses, they would have been given only the horizontal piece, according to historians of ancient execution methods, including LaGrange College professor John Granger Cook.

“For almost 1,000 years, the Christian church emphasized paradise, not Crucifixion,” two authors wrote in UU World magazine; in Slate, scholar Larry Hurtado claimed that “there was, in short, little to be gained in proclaiming a crucified saviour in that setting in which crucifixion was a grisly reality,” noting that “some early Christians tried to avoid reference to Jesus’ crucifixion.”

Yet there’s a reason this is surprising: Christian authors, poets and preachers wrote and spoke at great length about the significance and meaning of Jesus’ death on the cross. In the 2nd century, Christian thinker Justin Martyr wrote that “when they crucified Him, driving in the nails, they pierced His hands and feet; and those who crucified Him parted His garments among themselves,” emphasizing the humiliation and suffering of Jesus’ execution in a long dialogue with a non-Christian interlocutor. Tertullian, another prolific early Christian writer, also meditated at length on the crucifixion and its theological meaning.

This idea has some convinced followers. According to Jehovah’s Witnesses, for example, various authorities “have linked the cross with nature worship and pagan sex rites.” The Church of the Great God, another denomination, likewise claims that “long before the coming of Christ, pagans used the cross as a religious symbol.”

Yet there is no evidence that Christians intentionally borrowed the cross from pre-Christian cultic symbols.

While it is true that many ancient religions used symbols similar to the cross (and that Egyptian Christians even adapted the ankh, a hieroglyph for “life”), two intersecting lines are a simple and very common figure. This makes it difficult to assert that early Christians consciously adopted a particular sign rather than inventing one specifically referring to their unique story of Jesus’ death upon a cross. While it is easy to see similarities in religious artwork from various traditions, it is also easy enough to locate distinctions among them. The Christian cross, with all its associated symbols (anchors, letters, ploughs and more), is a distinct feature of Christian art.