The cause of his banishment is involved in obscurity. It was not unknown at Rome; but in his exile he refrains from alluding to it, except in dark allusions, out of fear of giving additional offence to the emperor.[739] He speaks of it as an indiscretion (_error_,) not a crime (_scelus_, _facinus_;[740]) as something which he had accidentally witnessed,[741] perhaps had indiscreetly told—a circumstance which deeply and personally affected Augustus, and inflicted a wound which he was unwilling to tear open afresh. He hints also that he fell a victim to the treachery of friends and domestics,[742] who enriched themselves by his ruin. There have been many conjectures[743] on this difficult point. Some have imagined an intrigue with the elder Julia, the profligate daughter of Augustus; but this is scarcely consistent with the manner in which Ovid himself speaks of his fault; and besides this, Julia was banished to Pandataria eight years before. The banishment of the younger Julia to Trimerus, about the same time with that of Ovid, would make it far more probable that his fall was connected with that of this equally profligate princess. Tiraboschi supposed that he had surprised one of the royal family in some disgraceful act; and some have even imagined that he might have witnessed such conduct on the part of the Emperor himself. Dryden believed that he accidentally saw Livia in the bath; and the author of the article in the Biographie Universelle, as well as Schoell,[744] surmise that he was in some way implicated in the fortunes of Agrippa Posthumus, and thus incurred the hatred of Livia and Tiberius. Whatever the cause may have been, the punishment was a cruel one, except for a crime of the deepest dye, and would never have been inflicted by the gentle Augustus so long as he was under the salutary influence of Mæcenas and his party. But in his old age he submitted to the baneful rule of the dark Tiberius and the implacable Livia. Any pretext, therefore, sufficed to remove one, who, from some cause or other, had excited their enmity. The alleged reason was the immorality of his writings; but they are not more immoral than those of Horace; and, besides, the worst of them had been published ten years before. Nor was the morality of the Emperor himself of such a character as to lead him to punish so severely a licentious poet in a licentious age. The exclusion of his works from the Palatine[745] library was a merited and more appropriate visitation. Nevertheless, this was made the pretext for a banishment, the misery of which was solaced by the empty mockery of the reservation of his civil rights.