Johanan - the crucified man from Jerusalem
The Bible says that Jesus was killed by being crucified - see Matthew's gospel chapter 27 verses 32-37; Mark's gospel chapter 15 verses 21-27, Luke's gospel chapter 23 verses 32-34, and John's gospel chapter 19 verses 16-20. In all, there are about thirty six references to crucifixion, and nearly thirty references to the cross as the means of execution.
Crucifixion was used as a means of execution in the Roman empire. The victim was stripped of his clothes and laid on the ground with his arms spread out on the cross bar. He would either be tied to the crossbar, or nailed to it, through the wrists. (Not through the palm of the hands. Don't let anyone tell you this involves a contradiction, or a mistake in the Bible: the Greek word for 'hand' has a wider range of meaning than the English word, and can include the wrist. There is no mistake or contradiction here.) The crossbar was then hoisted into place on the vertical, and the victim's feet were nailed in place. A sign could be hung on the top of the cross to say what crime he had committed.
If the victim relaxed, his lungs were held in the 'breathed out' position. The only way he could breathe in was by pushing up on the nail or nails that held his feet in position. We can only imagine how agonizing that was. As time went on, the victim was weakened by hunger, heat, dehydration, and perhaps loss of blood. His chest muscles grew weaker. It became harder and harder to take another breath. Eventually, he died of suffocation.
Sometimes, his legs would be broken. This prevented him from pushing himself up, so he could not breathe in, and died more quickly. The Bible records that when Jesus was crucified, the soldiers broke the legs of the two criminals who were crucified with him, but when they came to Jesus, he was already dead, and his legs were not broken. (See John's gospel chapter 19 verses 31-33).
Crucifixion was one of the most drawn-out and agonizing forms of execution ever devised. We even get our word 'excruciating' (literally, 'out of the cross') from the word for crucifixion.
Crucifixion was offensive to the Jews - they regarded anyone who was crucified as being under God's curse because they were being 'hung on a tree,' and the law of Moses said that anyone hung on a tree was cursed by God - see Deuteronomy chapter 21 verse 22-23. The early Church saw Jesus as being 'hung on a tree' when he was crucified, and therefore under God's curse - see Acts chapter 5 verse 30, Acts chapter 10 verse 39, and Galatians chapter 3 verse 13. Crucifixion was also offensive to the Romans and the Greeks because it was so degrading of the victim. It was not even used for ordinary criminals - only for slaves and rebels. Technically, the charge against Jesus was that he had claimed to be the king of the Jews - in other words, as far as the Roman authorities were concerned, he was a rebel. (See Matthew's gospel chapter 27 verses 11, 29, 37, Mark's gospel chapter 15 verses 2, 9, 12, 18 and 26, Luke's gospel chapter 23 verses 3, 37-38, and John's gospel chapter 18 verses 33 and 39, and chapter 19 verses 3, and 19-21).
In 1968, an ossuary (or bone box) was found in a tomb north of Jerusalem, inscribed with the name Johanan. It contained the remains of a man who had been crucified. Among the bones, there was a heel bone with an iron nail through it. The leg bones had both been broken - one was a clean fracture, but the other was smashed into pieces. This ossuary is a remarkable archaeological confirmation of the accuracy of the Bible's account of how Jesus was crucified.
For more about crucifixion and the Johanan ossuary Pilate inscription, see page 292 of 'Discoveries from Bible Times', by Professor Alan Millard. Some of the information on this page also comes from 'The Historical Reliability of John's Gospel', by Craig Blomberg, Apollos 2001, p. 254-5