Crassus was a lieutenant of the dictator Sulla. He was the main administrator behind the proscriptions held by Sulla, and Crassus had made a fortune seizing the property of the murdered men. A greedy entrepreneur, Crassus is said to have stopped at nothing to make money.
Crassus used his wealth to rise to prominence in Roman politics. He loaned out massive amounts of money to politicians, giving himself a great deal of sway over the borrowers.
In 71 BC, Crassus put down the slave revolt led by the gladiator Spartacus. All those captured were crucified. Only 5,000 escaped from the battle. The headed north, where they ran into the army of Pompey. The slaves were quickly overrun, and Pompey now claimed that he had defeated the slave army and saved Rome. Crassus did nothing to dispute this boast, for he saw an opportunity to form an alliance with the returning general.
In 60 BC, when the first triumvirate was formed, Crassus was invited into the alliance along with Pompey and Julius Caesar.