When he first applied himself to civil affairs, he defended the several causes of king Archelaus, the Trallians, and the Thessalians, before Augustus, who sat as judge at the trials. He addressed the senate on behalf of the Laodiceans, the Thyatireans, and Chians, who had suffered greatly by an earthquake, and implored relief from Rome. He prosecuted Fannius Caepio, who had been engaged in a conspiracy with Varro Mursena against Augustus, and procured sentence of condemnation against him. Amidst all this, he had besides to superintend two departments of the administration, that of supplying the city with corn, which was then very scarce, and that of clearing the houses of correctionSee before, in the reign of Augustus, c. xxxii. throughout Italy, the masters of which had fallen under the odious suspicion of seizing and keeping confined, not only travellers, but those whom the fear of being obliged to serve in the army had driven to seek refuge in such places.

He made his first campaign, as a military tribune, in the Cantabrian war.A. U. C. 728. Afterwards he led an army into the East,A.U.C. 734 where he restored the kingdom of Armenia to Tigranes; and seated on a tribunal, put a crown upon his head. He likewise recovered from the Parthians the standards which they had taken from Crassus. He next governed, for nearly a year, the province of Gallia Comata, which was then in great disorder, on account of the incursions of the barbarians, and the feuds of the chiefs. He afterwards commanded in the several wars against the Rhaetians, Vindelicians, Pannonians, and Germans. In the Rhaetian and Vindelician wars, he subdued the nations in the Alps; and in the Pannonian wars the Bruci, and the Dalmatians. In the German war, he transplanted into Gaul forty thousand of the enemy who had submitted, and assigned them lands near the banks of the Rhine. For these actions, he entered the city with an ovation, but riding in a chariot, and is said by some to have been the first that ever was honoured with this distinction. He filled early the principal offices of state; and passed through the quaestorship,A.U.C. 737 praetorship,A.U.C. 741 and consulatesA.U.C. 747 almost successively. After some interval, he was chosen consul a second time, and held the tribunitian authority during five years.

Surrounded by all this prosperity, in the prime of life and in excellent health, he suddenly formed the resolution of withdrawing to a greater distance from Rome.A.U.C. 748 It is uncertain whether this was the result of disgust for his wife, whom he neither durst accuse nor divorce, and the connection with whom became every day more intolerable; or to prevent that indifference towards him, which his constant residence in the city might produce; or in the hope of supporting and improving by absence his authority in the state, if the public should have occasion for his service. Some are of opinion, that as Augustus's sons were now grown up to years of maturity, he voluntarily relinquished the possession he had long enjoyed of the second place in the government, as Agrippa had done before him; who, when M. Marcellus was advanced to public offices, retired to Mitylene, that he might not seem to stand in the way of his promotion, or in any respect lessen him by his presence. The same reason likewise Tiberius gave afterwards for his retirement; but his pretext at this time was, that he was satiated with honours, and desirous of being relieved from the fatigue of business; requesting therefore that he might have leave to withdraw. And neither the earnest entreaties of his mother, nor the complaint of his father-in-law made even in the senate, that he was deserted by him, could prevail upon him to alter his resolution. Upon their persisting in the design of detaining him, he refused to take any sustenance for four days together. At last, having obtained permission, leaving his wife and son at Rome, he proceeded to Ostia,Ostia, at the mouth of the Tiber, about thirteen miles from the city, was founded by Ancus Martins. Being the port of a city like Rome, it could not fail to become opulent; and it was a place of much resort, ornamented with fine edifices, and the environs " never failing of pasture in the summer time, and in the winter covered with roses and other flowers." The port having been filled up with the depositions of the Tiber, it became deserted, and is now abandoned to misery and malaria. The bishopric of Ostia being the oldest in the Roman church, its bishop has always retained some peculiar privileges. without exchanging a word with those who attended him, and having enbraced but very few persons at parting.

From Ostia, journeying along the coast of Campania, he halted awhile on receiving intelligence of Augustus's being taken ill, but this giving rise to a rumour that he stayed with a view to something extraordinary, he sailed with the wind almost full against him, and arrived at Rhodes, having been struck with the pleasantness and healthiness of the island at the time of his landing there in his return from Armenia. Here contenting himself with a small house, and a villa not much larger, near the town, he led entirely a private life, taking his walks sometimes about the Gymnasia, The Gymnasia were places of exercise, and received their name from the Greek word signifying naked, because the contending parties wore nothing but drawers. without any lictor or other attendant, and returning the civilities of the Greeks with almost as much complaisance as if he had been upon a level with them. One morning, in settling the course of his daily excursion, he happened to say, that he should visit all the sick people in the town. This being not rightly understood by those about him, the sick were brought into a public portico, and ranged in order, according to their several distempers. Being extremely embarrassed by this unexpected occurrence, he was for some time irresolute how he should act; but at last he determined to go round them all, and make an apology for the mistake, even to the meanest amongst them, and such as were entirely unknown to him. One instance only is mentioned, in which he appeared to exercise his tribunitian authority. Being a constant attendant upon the schools and lecture-rooms of the professors of the liberal arts, on occasion of a quarrel amongst the wrangling sophists, in which he interposed to reconcile them, some person took the liberty to abuse him as an intruder, and partial in the affair. Upon this, withdrawing privately home, he suddenly returned attended by his officers, and summoning his accuser before his tribunal, by a public crier, ordered him to be taken to prison. Afterwards he received tidings that his wife Julia had been condemned for her lewdness and adultery, and that a bill of divorce had been sent to her in his name, by the authority of Augustus. Though he secretly rejoiced at this intelligence, he thought it incumbent upon him, in point of decency, to interpose in her behalf by frequent letters to Augustus, and to allow her to retain the presents which he had made her, notwithstanding the little regard she merited from him. When the period of his tribunitian authority expired,A.U.C. 752 declaring at last that he had no other object in his retirement than to avoid all suspicion of rivalship with Caius and Lucius, he petitioned that, since he was now secure in that respect, as they were come to the age of manhood, and would easily maintain themselves in possession of the second place in the state, he might be permitted to visit his friends, whom he was very desirous of seeing. But his request was denied; and he was advised to lay aside all concern for his friends, whom he had been so eager to quit.

He therefore continued at Rhodes much against his will, obtaining, with difficulty, thrqugh his mother, the title of Augustus's lieutenant, to cover his disgrace. He thenceforth lived, however, not only as a private person, but as one suspected and under apprehension, retiring into the interior of the country, and avoiding the visits of those who sailed that way, which were very frequent; for no one passed to take command of an army, or the government of a province, without touching at Rhodes. But there were fresh reasons for increased anxiety. For crossing over to Samos, on a visit to his step-son Caius, who had been appointed governor of the East, ihe found him prepossessed against him, by the insinuations of Marcus Lollius, his companion and director. He likewise fell under suspicion of sending by some centurions who had been promoted by himself, upon their return to the camp after a furlough, mysterious messages to several persons there, intended, apparently, to tamper with them for a revolt. This jealousy respecting his designs being intimated to him by Augustus, he begged repeatedly that some person of any of the three Orders might be placed as a spy upon him in every thing he either said or did.