Jesus's crucifixion is probably one of the most familiar images to emerge from Christianity. Good Friday, one of the holiest days in the Christian calendar, marks the event. But what was crucifixion? And why was Jesus killed that way?

Crucifixion was a Roman method of punishment. Suspended from a large cross, a victim would eventually die from asphyxiation or exhaustion - it was long, drawn-out, and painful. It was used to publicly humiliate slaves and criminals (not always to kill them), and as an execution method was usually reserved for individuals of very low status or those whose crime was against the state. This is the reason given in the Gospels for Jesus's crucifixion: as King of the Jews, Jesus challenged Roman imperial supremacy (Matt 27:37; Mark 15:26; Luke 23:38; John 19:19-22).

Crucifixion could be carried out in a number of ways. In Christian tradition, nailing the limbs to the wood of the cross is assumed, with debate centring on whether nails would pierce hands or the more structurally sound wrists. But Romans did not always nail crucifixion victims to their crosses, and instead sometimes tied them in place with rope. In fact, the only archaeological evidence for the practice of nailing crucifixion victims is an ankle bone from the tomb of Jehohanan, a man executed in the first century CE.

So was Jesus nailed to the cross?

Some early Gospels, such as the Gospel of Thomas, don't include the narrative of Jesus's crucifixion, choosing instead to focus on his teaching. But Jesus's death by crucifixion is one of the things that all four canonical Gospels agree on. Matthew, Mark, Luke, and John, all include the crucifixion event in their own slightly different ways.

None of the Gospels in the New Testament mentions whether Jesus was nailed or tied to the cross. However, the Gospel of John reports wounds in the risen Jesus's hands. It is this passage, perhaps, that has led to the overwhelming tradition that Jesus's hands and feet were nailed to the cross, rather than tied to it.