The Battle of the Silarius River occurred in 71 BC when the slave army of Spartacus was surrounded and destroyed by ten Roman legions under the command of Marcus Licinius Crassus, Gnaeus Pompeius Magnus, and Marcus Terentius Varro Lucullus. 47,000 of the 50,000 slaves were either killed in battle or crucified in its aftermath; Spartacus was among the crucified.
Background[]
In 72 BC, Spartacus' 70,000-strong slave army marched from Capua to Brundisium, where Spartacus expected for a fleet of 500 Cilician pirate ships to be waiting for him. The plan was for the Cilician fleet to carry Spartacus' army out of Italy and allow for the slaves to return to their homes as free people; Spartacus had already promised the Cilician envoy Tigranes Levantus a payment of 50 million sesterces in exchange for the pirates' assistance. Having been defeated at Mount Vesuvius and Metapontum, the Roman Senate prepared eight legions for a final campaign against the slaves. The Senate offered command of the legions to the retired patrician Marcus Licinius Crassus, the wealthiest citizen of Rome, and Crassus responded by demanding that he be elected First Consul and supreme commander of the Italian legions, and that the Senate give up its authority over the courts, effectively creating a dictatorship under Crassus. The populist senator Gracchus, seeking to prevent Spartacus from frightening the Senate into accepting Crassus' demands, made a deal with the Cilician fleet to allow for Spartacus and his army to leave Italy unmolested. However, Gracchus' pupil Julius Caesar was alienated by his mentor's collaboration with criminals, and he betrayed the plan to Crassus, who responded by bribing the Cilician fleet to withdraw rather than help Spartacus. At the same time, Gnaeus Pompeius Magnus' legions were withdrawn from Hispania and landed at Rhegium, while Marcus Terentius Varro Lucullus' legions were recalled from the East and landed at Brundisium. Tigranes warned Spartacus of these developments and of the Cilician fleet's betrayal, and Spartacus found himself forced to march north towards Rome rather than face Pompey and Lucullus' armies on two sides with his army's back to the sea. Spartacus thus marched north on Rome, knowing that, in doing so, Crassus would have the Senate's support in becoming an effective dictator with supreme command of the Roman Army.

Crassus speaking to his soldiers
Sure enough, the Senate - fearful of Spartacus' plans to free the slaves of the city of Rome - agreed to Crassus' terms, and Crassus swore to his military and his senators that he would punish Spartacus accordingly and crush his slave revolt. Crassus and his army marched south to meet Spartacus in battle, and, when he set up camp near present-day Strongoli, Calabria, he ordered that his army's positions be changed in order to frustrate Spartacus' scouts. He coordinated his plans with Pompey, whose legion would march 20 miles from their original positions in the west and through a hidden Apennine mountain pass behind Spartacus' lines, and Lucullus, whose army marched up from the south via forced night marches.
Battle[]

The Roman positions
Spartacus was unaware of the other Roman armies' approach, and his army deployed facing the Romans. When the Roman army began to advance into battle, Spartacus had his men send flaming haybales into the Roman lines, causing panic and forcing the Roman advance units to retreat. Many burned to death, while those who fell behind in the retreat were killed by the advancing slaves. The slaves then charged into battle with Crassus' army, and Spartacus rode into the fray on horseback before being unhorsed and being forced to fight on foot.

The Roman reinforcements advancing
Spartacus killed two centurions while trying to fight his way to Crassus, but the slaves began to take on heavy casualties, especially when the other two Roman armies charged into battle and attacked them from all sides. Spartacus' lieutenant Crixus was among the thousands of dead; around 36,000 died on the field of battle, while 11,000 were captured. Under 40 women (including Spartacus' wife Varinia) were captured, while the other women fled to the hills with their children.
Aftermath[]
After the battle, Crassus promised leniency to the male prisoners if they would identify the living or deceased body of Spartacus, but, before Spartacus could identify himself, his lieutenant Antoninus Siculus stood and proclaimed "I am Spartacus"; this was followed by several other prisoners making the same claim in solidarity. Angered by the slaves' defiance, Crassus ordered that the 11,000 prisoners be crucified along the Appian Way and up to the gates of Rome. Spartacus was the last to be crucified, and he was able to see Varinia and their child (who had been granted freedom after being stolen by Gracchus) just before he died on the cross.