Pro Roscio Amerino marked Cicero's first significant legal oration, given in defense of Sextus Roscius Jnr, brought to trial for the charge of parricide. Cicero's stirring defense, which resulted in his client's acquittal, appealed to his tumultuous political context, character and Roman values. Cicero weaves an alternative narrative of events, alleging that Roscius' relatives conspired to kill the wealthy Roscius Snr to claim his property. These relatives, Magnus and Capito, allegedly worked in collusion with the high-ranking official Chrysogonus to legally seize the defendant's inheritance through the era's terrifying proscriptions campaign. Speaking out against Sulla's regime, Cicero also takes great care in flattering the dictator for his personal and professional safety.
Cicero antagonizes these relatives and Chrysognus through carefully calculated character assassination, while elevating Roscius Jnr as a paragon of rustic country values and filial piety. The appeal to core Roman values, such as pietas and honestas, is central to Cicero's argument. He aligns or divorces the characters of interested parties with these values, successfully influencing the judges' verdict. He also meditates upon the extraordinary violation of these values represented by the crime of parricide, requiring a level of depravity incongruous with Roscius Jnr's good character. The Pro Roscio Amerino closes with a poignant appeal to pathos, warning the judges that delivering a guilty verdict will set up an unjust precedent for manipulating the descendants of those proscribed.
In Verrem is another notable oration, wherein Cicero represented the province of Sicily to prosecute the corrupt governor Verres for changes of corruption and extortion. The case was a success and brought Cicero much renown as both an orator and advocate.
Cicero's Catiline Orations were significant for their rhetorical brilliance and historical significance. During In Catilinam, Cicero reveals to the Roman Senate a plot by fellow senator Catiline to overthrow the government. The famous fresco by Cesare Maccari depicts the moment during Cicero's speech where the senators rise from their seats and single out Catiline on account of his crimes.
Other notable orations include the Pro Caelio, Pro Milone and the Phillipics against Marc Antony (largely responsible for Cicero's prosecution and execution).