Crucifixion was a painful and humiliating death, but it was never intended to be a form of torture used to extract information from enemies; the Romans preferred to bribe enemies rather than pretend to drown them. Water-boarding is torture, and if it needs to be done 193 times in the space of 30 days, it does not work to extract information.
Crucifixion was a form of punishment reserved almost entirely for slaves. Early in Spartacus' war, Gaius Verres' crucifixion of Publius Gavius, who had turned out to be a citizen, became a scandal thanks to Cicero; Verres had claimed the man was a slave that had run away to spy for Spartacus, but the truth will forever be lost in the mist of history and Verres' lies.
Although in the movie, Spartacus' supporters - run-away slaves - were the ones crucified, Strauss' brilliant history of the war reminded me that Spartacus himself also used crucifixion.
Towards the end of his war, trapped on the Melia Ridge by Crassus' army, according to Appian (B.C., 1.119):
Spartacus, who was expecting a reinforcement of horse from somewhere, no longer went into battle with his whole army, but harassed the besiegers by frequent sallies here and there. He fell upon them unexpectedly and continually, threw bundles of fagots into the ditch and set them on fire and made their labour difficult. He also crucified a Roman prisoner in the space between the two armies to show his own men what fate awaited them if they did not conquer. But when the Romans in the city heard of the siege they thought it would be disgraceful if this war against gladiators should be prolonged. Believing also that the work still to be done against Spartacus was great and severe they ordered up the army of Pompey, which had just arrived from Spain, as a reinforcement.Spartacus' war is also sometimes called the Third Servile War, or third revolt of slaves during the late Republic; crucifixion had been used as a punishment during the earlier wars. Strauss feels that the 'warning' worked, and helped galvanize Spartacus' men at least in the short term. He also makes the point that it was an age of massacres. Crucifixion, because of the association with Jesus, has many connotations today - at the time it was simply another form of killing one's enemies.
The run away slaves were not crucified immediately following Spartacus' death in his last battle. Those that were famously crucified along the road from Capua to Rome were a smaller band of 6,000 men that had fled from the battle site in Lucania, and hidden out in the mountains. Crucifixion was an extra punishment - and disincentive to others - meted out by Crassus for his having had to hunt them down. The 6,000 were captured in the mountains, then marched down to Capua - where the rebellion had, as Strauss notes, started in the gladiatorial school. He also notes that 6,000 is, typically of ancient numbers, probably an approximation.
Barry Strauss' biography of Spartacus and history of the last Servile War makes for fascinating reading. I know that many readers of this blog are interested in crucifixion, and they will find a great deal more about it in his book.
Some of the other examples of ancient crucifixion Strauss mentions in passing include the following, making it clear that it was not an uncommon means of mass executions:
* Augustus crucifying 6,000 of Sextus Pompey's rowers in 36 BC, all slaves.
* Alexander Jannaeus, king of Judea, on the advice of Diogenes of Judea, crucified 800 Pharisees who had sided with the Seleucids during the civil war of 86 BC (the source is Josephus, and this dissertation has much more information about crucifixion, particularly in Israel)
* 2,000 crucified by Quintilius Varus in Judaea, as he put down a rebellion following Herod the Great's death (the source is Josephus).
* Countless accounts of crucifixion are recorded during the AD 70 siege of Jerusalem, with one source claiming that 500 were crucified a day.
* Alexander the Great crucified 2,000 at Tyre in 326 BC. Darius also used crucifixion, although there are some debates about the exact nature of these pre-Roman examples, which were akin to hanging someone by the arms, and could be done from a tree as well as on a cross).
Perhaps the most interesting observation Strauss makes is how expensive it would have been to crucify 6,000 men, and that Crassus, who presumably paid for this form of execution himself, was making a statement to future slaves that might be tempted to rebel, as well as staking his claim politically. It was a deterrent, and a dramatic visual one, reminding others not to try to follow in Spartacus' footsteps each time they went up and down the Roman road. It was capital punishment as an ostentatious display of Crassus' wealth and theatre on a grand scale. The choice of starting the miles of evenly spaced crucified rebels at Capua is unlikely to have been an accident.
Strauss covers most of the available information we have about crucifixion, including details we tend to forget, such as dog carrying away pieces of crucifixion victims because those considered lower in the social pecking order were crucified at ground level rather than a few feet above ground level. I'd also forgotten that the Romans, according to Pliny (N.H. 28.11.46), had kept relics from crucifixions - nails, rope, hair clippings - as a 'magic' charm to ward off malaria.
I highly recommend Barry Strauss' account of Spartacus:
The Spartacus War: The Revolt of the Gladiators - Amazon.co.uk
The Spartacus War - Amazon.com