At twenty-five, he pleaded his first cause,[787] and in the following year defended S. Roscius of Ameria; but his constitution was not strong enough to bear great exertion. His friends, therefore, induced him to travel, and he determined to pass some time at Athens.[788] There was also another reason for this recommendation. His courageous defence of Roscius had provoked the enmity of Chrysogonus, a creature of Sulla, and it was therefore dangerous for him to remain at Rome. He was accompanied by his brother Quintus,[789] and found Pomponius Atticus residing there, who afterwards became his most intimate friend. From Athens he travelled to Asia and Rhodes, employing his time in the cultivation of oratory, his principal study at Athens having been philosophy. From Asia he returned to Rome[790] with improved health and an invigorated constitution; where he found a powerful rival, as an orator, in Hortensius, who was then at the zenith of his popularity. As soon as he was old enough,[791] he was elected quæstor, and the province of Sicily was allotted to him. In the exercise of this office, the unusual mildness and integrity of his administration endeared him to the provincials; whilst the judgment with which he regulated the supplies of corn from the granary of Rome, gained him equal credit with his fellow-countrymen. It was during his stay in Sicily that his love of antiquarianism was gratified by the discovery of the tomb of Archimedes.[792] On his return home[793] he resumed his forensic practice: and in B. C. 70 was the champion of his old friends, the Sicilians, and impeached Verres, who had been prætor of Syracuse, for oppression and maladministration. In the following year[794] he was elected curule ædile by a triumphant majority. In the celebration of the games which belonged to the province of this magistrate, he exhibited great prudence by avoiding the lavish expenditure in which so many were accustomed to indulge, whilst, at the same time, no one could accuse him of meanness and illiberality. In the year B. C. 67, he obtained the prætorship, and notwithstanding the judicial duties of his office, defended Cluentius. Hitherto his speeches had been entirely of the judicial kind. He now for the first time distinguished himself as a deliberative orator, and supported the Manilian law which conferred upon Pompey, to the discomfiture of the aristocratic party, the command in chief of the Mithridatic war. The great object of his ambition now was the consulship, which seemed almost inaccessible to a _new man_. As all difficulties and prejudices were on the side of the aristocratic party, his only hope of surmounting them was by warmly espousing the cause of the people.