Another instance of the dangers of Capri involved Tiberius’s favorite companions, for, according to reports, he most enjoyed the society of Greek philosophers, grammarians, poets, and astrologers. At meals he would carry on learned conversations with them, raising questions that had occurred to him in his daily reading. As could be expected, given that he was not simply another scholar but the emperor of Rome, there was naturally great competition for his favor. Gaining it could mean fame and riches, but the pursuit was also dangerous, as the companions vying for it used every means at their disposal. Suetonius writes that the grammarian Seleucus inquired of the emperor’s servants what their master was reading, so that with advance preparation he could dazzle Tiberius with his knowledge. Unfortunately, he seems to have overdone it. The emperor, already weary of the opportunistic behavior of aristocrats in Rome, detested it even more in his inner circle on Capri, so when his suspicions were aroused he looked into the matter. Seleucus was banned from his daily company and later forced to commit suicide.
Caligula apparently had more success when he took part in the learned discussions on Capri. We are told that he had a profound knowledge of the works with which educated men of the day were expected to be familiar. Josephus writes that “he was, moreover, a first-rate orator, deeply versed in the Greek and Latin languages. He knew how to reply impromptu to speeches that others had composed after long preparation, and to show himself instantly more persuasive than anyone else, even where the greatest matters were debated. All this resulted from a natural aptitude for such things and from his adding to that aptitude the practice of taking elaborate pains to strengthen it.” There is no question that he had enjoyed a good education from his earliest years. As was customary in aristocratic families, Caligula probably received instruction from tutors, who were usually Greek slaves or freedmen. He may have been influenced by the reported interest of his father, Germanicus, in scholarship and literature, or perhaps his interest was spurred by his journeys as a child to the centers of ancient learning in Greece and Egypt. It appears that he also made use of his time on Capri to further his studies. According to Josephus again: “Being the grandson of the brother of Tiberius… he was under a great compulsion to apply himself to education, because Tiberius himself also had conspicuously succeeded in attaining the highest place in it. Gaius followed him in his attachment to such noble pursuits, yielding to the injunctions of a man who was both his kinsman and his commander-in-chief” (Jos. Ant. 19.208–9).
No accounts of the later period of Caligula’s rule mention a particular interest in learning. It is thus probably no mistake to assume that in this respect, too, he skillfully adapted his behavior on Capri to the prevailing circumstances and showed an interest in the subjects Tiberius preferred, especially since he was clearly endowed with the requisite intellectual gifts. And he did improve his relationship with the emperor, which was no doubt quite strained to begin with because of the general political atmosphere and the particular family constellation. At least their relationship appears to have grown better during Caligula’s first two years on Capri. Although Tiberius did not display any particular friendship to his great-nephew and potential successor, neither was he openly hostile.
In the year 33, that is, in the same period when his mother and remaining brother met their deaths, Caligula was appointed quaestor, the lowest honorary political office, which carried with it automatic membership in the Senate. He was only twenty, under the usual minimum age for the quaestorship. At the same time he was given permission to be a candidate for other offices, five years before reaching the required age. This was a privilege traditionally granted to princes of the imperial family and could thus be interpreted as a positive signal for his position. And finally Tiberius had arranged for Caligula to marry Junia Claudilla (or Claudia) during a visit to Antium. She was the daughter of Marcus Junius Silanus, a former consul who had gained attention by introducing servile and flattering resolutions in the Senate. He was considered one of Tiberius’s closest associates and received the right to cast his vote first. This was an extraordinary honor that gave him the highest standing in the Roman aristocracy. In political terms such an honor was not without its dangers, as shown by the emperor’s behavior in the Senate described above. Nevertheless Silanus was clearly able to use his standing skillfully.
Caligula’s marriage would last only a short time, and it is impossible to determine how much it meant to him. Nor can anything positive be deduced from it about Tiberius’s plans for the succession. Each of Caligula’s brothers had been married to a cousin (Nero to Julia, a granddaughter of Tiberius, and Drusus to Aemilia Lepida, a great-granddaughter of Augustus) and thereby gained the prestige conferred by an additional connection with the ruling family. No further young ladies of appropriate background were available, but the idea that one of these might take Caligula as a second husband seems not to have been considered. Julia was perhaps excluded because her testimony had contributed to Nero’s downfall. Aemilia Lepida might have been a candidate, for her participation in the fall of Drusus (III) was not discussed until years later, but both women remarried aristocrats unconnected to the imperial family. Caligula’s wife, Junia Claudilla, could boast of no comparable ancestry. Nor did the marriages of his sisters, which were certainly based on the emperor’s plans, reveal any particular favor. Only Agrippina the Younger married Gnaeus Domitius Ahenobarbus, a grandson of Marcus Antonius and Octavia, Augustus’s sister. The later emperor Nero was the offspring of this marriage. Drusilla was married to Lucius Cassius Longinus, descended from an old aristocratic family, while Livilla’s husband, Marcus Vincius, came from a less illustrious background. Tiberius’s marriage policy with regard to the children of Germanicus and Agrippina can thus be summed up as follows: None of the marriages he arranged had the slightest effect on the possibility that his own grandson, Tiberius Gemellus, might become emperor.
Caligula’s future remained uncertain, since no doubt he stood in the way of Tiberius’s biological grandson, because of both his own descent and his popularity in Rome. During his stay on Capri he was further awarded two religious offices that were a customary part of a Roman senator’s career, but they also permit no conclusions about the emperor’s plans for him. Finally, in the year 35, Tiberius drew up a will, whose contents can be described as most definitely leaving both options open. Caligula and Gemellus received equal shares of his inheritance, in a decision that was no decision at all. Even at that point, however, the conclusion that emerged two years later upon Tiberius’s death must have been evident. The imperial office was not divisible, yet according to the will the vast imperial assets would have had to be divided, even though by this time they constituted a central part of the emperor’s authority and had taken on a character that in the modern sense of the word was public and no longer private. If it is not to be read as documentary evidence that Tiberius was incapable of making up his mind — in which case the emperor could have dispensed with it entirely — then the message it conveyed was clear: The question of the succession was to remain open.