Crassus
Crassus was elected praetor and headed to Picenum to put an end to the slave revolt with ten legions, six new and four old. Crassus correctly assumed the slaves would head north to the Alps and so positioned most of his men to block this escape. Meanwhile, he sent his lieutenant Mummius and two new legions south to pressure the slaves to move north. Mummius had been explicitly instructed not to fight a pitched battle. He, however, had ideas of his own, and when he engaged the slaves in battle, suffered defeat.
Spartacus routed Mummius and his legions. They lost not only men and their arms, but when they returned to their commander, the survivors suffered the ultimate Roman military punishment -- decimation, by order of Crassus. All the men who had been involved in the disgraceful operation were divided into groups of ten and then drew lots. The unlucky one in ten was then killed.
Meanwhile, Spartacus turned around and headed towards Sicily, planning to escape on pirate ships, which he had hired, not knowing that the pirates had already sailed away. At the Isthmus of Bruttium, Crassus built a wall to block Spartacus' escape. When the slaves tried to break through, the Romans fought back killing about 12,000 of the slaves while losing only seven of their own.
Slaves vs. 3 Roman Armies
When Spartacus learned that Crassus' troops were to be reinforced by another Roman army brought back from Spain, he decided it was time to make a break for it. He and his slaves fled north with Crassus at their heels. His escape route was blocked at Brundisium by a third Roman force recalled from Macedonia. There was nothing left for Spartacus to do but to try to beat Crassus' army in battle. The Spartacans were quickly surrounded and butchered, although many men escaped into the mountains. Only a thousand Romans died.
Six thousand of the fleeing slaves were captured by Pompey's troops and crucified along the Appian Way from Capua to Rome. Spartacus' body was not found.
Because Pompey performed the mopping up operations, he, not Crassus, got credit for suppressing the rebellion. Jealousy and competition between these two rich and powerful men were to lead to changes in the power structure of Rome.