In 63 BC Marcus Tullius Cicero (106-43 BC), orator, statesman and patriot, attained the rank of consul and in that capacity exposed to the Roman senate the plot of Lucius Sergius Catilina (approx. 108-62 BC) and his friends to overthrow the government of Rome.

It came about in this way. Catiline, who was running for consulship a second time after having lost the first time around, tried to ensure his victory by resorting to blatant and excessive bribery. Cicero in self-righteous indignation issued a law prohibiting shenanigans of this kind. It was obvious to all that the law was directed specifically at Catiline. Catiline, in turn, conspires with some of his cronies to murder Cicero and the key men of the senate on the day of the election. Cicero discovered the plan and postponed the election to give the senate time to discuss the attempted coup d'état.

The day after the election was supposed to be held, Cicero addressed the senate on the matter and Catiline's reaction was immediate and violent. In response to Catiline's behavior, the senate issued a senatus consultum ultimum, a kind of declaration of martial law invoked whenever the senate and the Roman Republic were in imminent danger from treason or sedition. Ordinary law was suspended and Cicero, as consul, was invested with absolute power.

When the election was finally held, Catiline lost again. Anticipating the bad news, the conspirators had already begun to assemble an army, made up mostly of Sulla's veteran soldiers. The nucleus of conspirators was also joined by senators whose profligate tastes left them permanently without funds. The plan was to initiate an insurrection in all of Italy, put Rome to the torch and to kill as many senators as they could.

Through some crafty moves of his own, Cicero knew exactly what was being planned. On November 8 Cicero called for a meeting of the senate in the Temple of Jupiter in the Capitol, which was used for this purpose only when great danger threatened. Catiline had the temerity to attend also. It was then that Cicero delivered directly to Catiline his famous:

ORATIO IN CATILINAM PRIMA IN SENATU HABITA

As political orations go, this was short and to the point. The opening remarks are still remembered and used after 2,000 years:
Quo usque tandem abutere, Catilina, patientia nostra? Quam diu etiam furor iste tuus nos eludet?

When, O Catiline, do you intend to stop abusing our patience? How long is that madness of yours still to mock us?

Catiline tried to reply after the speech, but senators repeatedly interrupted him. He ran from the temple, hurling threats at the senate. Later he left the city and went to the camp of Manlius, who was in charge of the army of rebels. The next morning Cicero assembled the people, and delivered to them his:

ORATIO IN CATILINAM SECUNDA AD POPULUM

Here he informed the citizens of Rome that Catiline has left the city, not in exile as it was rumored, but to join up with his illegal army. He described the conspirators as rich men who are in debt; men eager for power and wealth; Sulla's veterans; ruined men, hoping for any change; criminals; profligates and other men of Catiline's ilk.

But the people of Rome have nothing to fear because he, the consul, and the gods will protect the state.

Meanwhile, Catiline joins up with Manilus, commander of the rebel force. When the senate was informed of these developments, they declare the two of them public enemies. Antonius with troops loyal to Rome, followed Catiline, while Cicero remained at home to guard the city. Eventually Cicero obtained documents and confessions of many of the conspirators and the whole matter was presented to the people in his:

ORATIO IN CATILINAM TERTIA AD POPULUM

The city should rejoice because it has been saved from a bloody rebellion. He asked for nothing for himself but grateful remembrance of the city for what he has done. He acknowledged that this victory was more difficult than one in foreign lands, because the enemies were citizens of Rome.

POSTSCRIPT

During the battle that took place between the 2nd and 3rd orations, Catiline saw that he would lose and in consequence threw himself into middle of the Roman troops and was slain in 62 BC.

References:

http://www.uah.edu/student_life/organizations/SAL/claslattexts/cicero/incatilinam1.html Latin Text

http://www.perseus.tufts.edu/ Latin Text; Translation and analysis

http://community.middlebury.edu/~harris/LatinAuthors/Cicero.html Biography