 During Gaius Julius Caesar’s Consulship of 59 BC, Marcus Petreius allied himself with Caesar’s bitter opponent Marcus Porcius Cato (the Younger).From 55 BC, Petreius and Lucius Afranius administered the Spanish provinces as Legates, while the official governor Gnaeus Pompeius Magnus remained in Rome.After the outbreak of the Civil War in 49 BC, Petreius and Afranius marched against Caesar, who for his part wished to secure Spain before moving against Pompey in Greece.