Marcus Caelius Rufus (28 May 82 BC – after 48 BC) was an orator and politician in the late Roman Republic. He was born into a wealthy equestrian family from Interamnia Praetuttiorum (Teramo), on the central east coast of Italy. He is best known for his prosecution of Gaius Antonius Hybrida in 59 BC. He was also known for his trial for public violence (de vi publica) in March 56 BC, when Cicero defended him in the extant speech Pro Caelio, and as both recipient and author of some of the best-written letters in the ad Familiares corpus of Cicero's extant correspondence (Book 8). He may be the Rufus named in the poems of Catullus. Life and career In his twenties Caelius became associated with Crassus and Cicero, while he was also briefly connected to Catiline and his conspiracy. Caelius first achieved fame through his successful prosecution in 59 BC of Gaius Antonius Hybrida for corruption. Antonius Hybrida had served as consul with Cicero for the year 63 BC, and his prosecution was a sign of the negative political atmosphere towards Cicero at the time. A year later, in 58 BC, Cicero was exiled, through the efforts of his political enemy Publius Clodius Pulcher. Cicero was recalled from exile in 57 BC with the help of his ally Titus Annius Milo, who was tribune at the time. Sometime around 57 BC, Caelius and Clodia are believed to have had an affair which ended acrimoniously. In 56, Caelius was prosecuted for vis (violence), specifically for murdering an ambassador. He was successfully defended by Crassus and, more famously, Cicero, whose speech Pro Caelio argued that the prosecutor, Atratinus, was being manipulated by Clodia to get revenge on Caelius for an affair gone wrong. Caelius was tribune of the plebs in 52 and curule aedile in 50. During this period he wrote a series of witty and informative letters to Cicero, who was serving as proconsul of Cilicia at the time. After much hesitation, Caelius sided with Julius Caesar against Pompey in the civil war, warning Cicero accordingly not to align his fortunes with Pompey: in 48 BC he was rewarded with the office of praetor peregrinus (“judge of suits involving foreigners”). However, when his proposed program of debt relief was opposed by the Senate and he was suspended from office, he joined in a rebellion against Caesar which was quickly crushed. It