Crucifixion was one of the worst punishments in the ancient world. It was made for a very slow painful death. Rome is most famously known for crucifixion, but they may have gotten it from the Carthaginians. Crucifixions were reserved for heinous crimes and treason. Roman citizens were exempt unless they committed a very, very serious crime. Before a crucifixion, the condemned is scourged with a whip and made to carry the crossbeam in Roman crucifixions. They were usually offered a drink to ease some suffering. There are many theories as to how one actually dies on the cross, some may die from exposure and dehydration. If the arms are raised high enough, it affects your ability to breathe. To breath properly, you have to lift and lower yourself with each breath (which is very painful when you’re nailed up there!). Some even theorize that fluid will build up in the pericardium of the heart and they’d die of a heart attack. After a while, guards would usually break the condemned’s legs to end their suffering, called “crucifracture”.
There were different types of crosses, one was just an upright pole, and one looked like an upright “T”. Archaeologists have little physical evidence of crucifixion, presumably because the bodies were either left to the elements or dumped in the city’s garbage, but they found a heel bone with a crucifixion nail embedded in it. The crucifixion nails were taken usually because they were thought to have healing powers. Jesus Christ is the most famous victim of crucifixion, but others were known too like Spartacus’ men after the slave revolt they caused.