T he policy—or was it caprice?—which made Tiberius leave his capital, and spend the last eleven years of his life in the rocky island of Capreae, is one of the puzzles of history. Neither those who, following Tacitus and Suetonius, hold him to have been a monster of wickedness, nor those, chiefly to be found among modern writers, who regard him as a wise prince who has been cruelly maligned, are able to account for it satisfactorily. Among the causes suggested are, as has been already mentioned, his impatience of the influence exercised over him by his mother. Another is the influence of Sejanus, who hoped thus to increase his own power, but who could hardly have carried his point, unless he had found the Emperor already well disposed to the plan. Among the private motives which were mentioned as actuating him was personal vanity, or, rather the unwillingness to display to the eyes of the public a face that had been once handsome, but was now disfigured with disease. In this there was nothing worse than weakness; a darker motive that has been attributed to him, was the desire to engage in disgraceful pleasures in secret. Whatever the cause of his retirement from Rome, he never returned to it, though he sometimes visited the neighbourhood, coming once as far as the Gardens of Caesar on the right bank of the Tiber. His mother's death did not bring him back, nor did he return even when he learnt from the conspiracy of Sejanus what a danger he might incur by his protracted absence from his capital.
The island, now a favourite resort of English visitors to the south, was admirably suited to the solitude which, for some reason or other, he affected. It had only one landing place, and that so limited in extent that no one could approach it without being seen. The cliffs were high and inaccessible, and the sea that surrounded it was deep. The preparations made for fitting this island for his residence were of the costly style which was customary in Roman life. Twelve villas, named after the twelve great gods and goddesses of the Roman pantheon, crowned as many heights in the island. The largest and the most defensible against attack—no slight recommendation in the eyes of the jealous tyrant—seems to have been the Villa of Jupiter. It was here that he awaited the news of the coup d' etat by which he struck down Sejanus; it was in this that he remained shut up till he felt himself again safe on his throne. Strange stories are told of the jealousy with which he guarded the secrecy of this retreat against even casual and perfectly harmless visitors. A fisherman had contrived to elude the guards and make his way to the house in which the Emperor had taken up his abode in order to make him a present of a mullet of unusual size which he had caught. Tiberius ordered the man's face to be rubbed with the fish. The poor wretch was overheard to congratulate himself that he had not also offered a very large lobster which he had also caught. The lobster was brought, and set to mangle the man's face with its claws. It was his practice, it was said, to have his victims thrown from the cliffs into the sea. If any remains of life were found in them there were boatmen in readiness below to dash out their brains. To such a pitch of frantic rage and fear did he come, after the fate of Sejanus, that on one occasion he ordered an old friend from Rhodes, whom he had himself sent for, to be seized and tortured. When he discovered his mistake he silenced the anticipated reproaches by ordering the man to be put to death.
Of the companions of his retirement not the least cherished were the astrologers, in whose power to foretell the future he placed a confidence which seems hardly consistent with his powerful intellect. One of these, Thrasyllus by name, had gained his confidence in a very curious way. Tiberius, if he had any reason to suspect false dealing in the soothsayer whom he had consulted, used to give a signal to an attendant, a man of remarkable strength, that the prophet was to be thrown over the cliff into the sea. Thrasyllus on one occasion had drawn his patron's horoscope, and the attendant was in waiting for the signal of death. "What of your own?" asked Tiberius. The man calculated it with elaborate care, and then, with every sign of terror, declared that his own last hour was close at hand. The Prince was delighted at his foresight, and made him thenceforward his most trusted adviser when the secrets of the future were in question.
It was not at Capreae, however, that the Emperor breathed his last. He had gone from place to place with the restlessness that often comes before the end, and had settled down for a time in the country house which the great soldier Lucullus had built near the promontory of Misenum. Among his visitors there was a skilful Greek physician, whose advice he was accustomed to ask, though without putting himself under his care. The man came to make his farewell, took the Emperor's hand as if he would have kissed it, and contrived to feel his pulse. Tiberius perceived it, but made no sign—he was accustomed to conceal his resentment. But he kept his place at table longer than usual, and retained his friend to share the festivity. But the man was not deceived. He told the major-domo that the Emperor could not last two days more. Despatches were sent to the provinces, and other preparations were made for a new reign. On the 16th of March Tiberius became insensible. Every one believed him to be dead, and Caligula, his successor, came forth to receive the congratulations of the little court. Then, like a thunderbolt, came the news that the Emperor had recovered sight and speech, and was asking for food. A general panic followed; the courtiers dispersed, seeking to assume an expression of ignorance, or of the decent grief that befitted the attendants of a dying prince. Caligula, who, but a moment before, had seemed to grasp the delights of power, was now sunk in the depths of despair. Only Macro retained his presence of mind. He ordered the attendants to pile rugs and coverlets on the old man till he was suffocated. Tiberius was in his seventy-seventh year of his life, and the twenty-third of his reign.