Catiline, or Lucius Sergius Catilina, a Roman patrician, an able man, but unscrupulously ambitious; frustrated in his ambitious designs, he formed a conspiracy against the State, which was discovered and exposed by Cicero, a discovery which obliged him to leave the city; he tried to stir up hostility outside; this too being discovered by Cicero, an army was sent against him, when an engagement ensued, in which, fighting desperately, he was slain, 62 B.C.