Born from a noble but impoverished family, he served in the Social War with Pompey and Cicero, under Pompeius Strabo. He also supported Sulla in the civil war of 84-81 BC. Catiline was praetor in 68 and governed Africa in the following two years. Upon his return he was prosecuted for abuse of power, but eventually acquitted, then in 66 was accused of a conspiracy with Autronius and Sulla, although we are unclear on the details. After being defeated by Cicero in the consular election for 63, he championed the cause of aristocrats and Sullan veterans down on their luck. He also began to organize a new and larger conspiracy.
In 63 BC Cicero, who was consul at the time, discovered and denounced his conspiracy to the Senate, and Catiline had to flee from Rome. In January 62 BC he and his fellows were intercepted by the Roman army near Pistoria (now Pistoia), and he died in the subsequent battle.
The conspiracy inspired several literary works: Cicero wrote down his orations to the Senate, which became a widely studied example of eloquence and rhetoric; also Sallust wrote an historical account of the events.