Mutinies in Illyricum and on the Rhine. Two serious mutinies followed the accession of Tiberius, one in the army stationed in Illyricum, the other among the legions on the Rhine. Failure to discharge those who had completed their terms of service and the severity of the service itself were the grounds of dissatisfaction. The Illyrian mutiny was quelled by the praetorian prefect Lucius Aelius Seianus; the army of the Rhine was brought back to its allegiance by Germanicus, the son of Drusus, whom Tiberius had adopted at the command of Augustus in 4 A. D. He had married Agrippina, daughter of Agrippa and Julia, and was looked upon as the heir of Tiberius in preference to the latter’s younger and less able son, Drusus.
The campaigns of Germanicus, 14–17 A. D. To restore discipline among his troops and relieve them from the monotony of camp life, as well as to emulate the achievements of his father, Germanicus, without the authorization of Tiberius, led his army across the Rhine. The German tribes were still united in the coalition formed in the time of Varus, and, under their leaders Arminius and Inguiomerus, offered vigorous opposition to the Roman invasion. Nevertheless, in three successive campaigns (14–16 A. D.), Germanicus ravaged the territory between the Rhine and the Weser and inflicted several defeats upon the Germans. Still Arminius and his allies were by no means subdued, and the Romans had sustained heavy losses. One army had narrowly escaped the fate of the legions of Varus, and twice had the transports of Germanicus suffered through storms in the North Sea. For these reasons Tiberius forbade the prolongation of the war and recalled Germanicus. With his departure, each of the three Gauls was made an independent province, and two new administrative districts called Upper and Lower Germany, under legates of consular rank, were created on the left bank of the Rhine. Freed from the danger of Roman interference, the Germanic tribes led by [pg 228]Arminius now engaged in a bitter struggle with Marbod, king of the Marcomanni, which ultimately led to the overthrow of the latter’s kingdom. Not long afterwards Arminius himself fell a victim to the jealousy of his fellow tribesmen (19 A. D.).
Eastern mission and death of Germanicus, 17–19 A. D. After his return from Gaul, Germanicus was sent by Tiberius to settle affairs in the East, where the Armenian question had again become acute. While he was in Syria, a bitter quarrel developed between himself and Piso, the legate of the province. Accordingly, when Germanicus fell ill and died there, many accused Piso of having poisoned him. Although the accusation was false Piso was called to Rome to stand his trial on that charge, and, finding that the popularity of Germanicus had biased popular opinion against him, and that Tiberius refused him his protection because of his attempt to assert his rights by armed force, he committed suicide. Agrippina, the ambitious wife of Germanicus, believed that Tiberius from motives of jealousy had been responsible for her husband’s death. She openly displayed her hostility to the princeps, and by plotting to secure the succession for her own children, helped to bring about their ruin and her own.
The withdrawal of Tiberius from Rome, 26 A. D. The decision of Tiberius to leave Rome in 26 A. D. and take up his residence on the island of Capri had important consequences. One was that the office of city prefect, who was the representative of the princeps, became permanent. It was filled by a senator of consular rank who commanded the urban cohorts and had wide judicial functions.
The plot of Seianus. In the second place the absence of Tiberius gave his able and ambitious praetorian prefect Aelius Seianus encouragement and opportunity to perfect the plot he had formed to seize the principate for himself. He it was who concentrated the praetorian guard, now 10,000 strong, in their camp on the edge of the city, and paved the way for their baneful influence upon the future history of the principate. Having caused the death of Drusus, the son of Tiberius, by poison, in 23 A. D., he intrigued to remove from his path the sons of Germanicus, Drusus and Nero. They and their mother Agrippina were condemned to imprisonment or exile on charges of treason. In 31 A. D. Seianus attained the consulate and received proconsular imperium in the provinces. He allied himself with the Julian house by his betrothal to Julia, the grand-daughter of [pg 229]Tiberius. But in the same year the princeps became aware of his plans. Tiberius acted with energy. Seianus and many of his supporters were arrested and executed.
The last years of Tiberius. The discovery of Seianus’ treachery seems to have affected the reason of the aging princeps. His fear of treachery became an obsession. The law of treason (lex de maiestate) was rigorously enforced and many persons were condemned to death, among them Agrippina and her sons. The senators lived in terror of being accused by informers (delatores), and in their anxiety to conciliate the princeps they were only too ready to condemn any of their own number.
The memory of his later years caused Tiberius to pass down in the traditions of the senatorial order, represented by Tacitus and Suetonius, as a ruthless tyrant, and to obscure his real services as a conscientious and economical administrator. His parsimony in expenditures of the public money won him unpopularity with the city mob, but was a blessing to the provincials to whose welfare Tiberius directed particular attention, while he vigorously protected them against the oppression of imperial officials. During his rule the peace of the empire was disturbed only by a brief rising in Gaul (21 A. D.) and a rather prolonged struggle with Tacfarinas, a rebellious Berber chieftain, in Numidia (17–24 A. D.).
II. Caius Caligula, 37–41 a. d.
Accession. Tiberius left as his heirs his adoptive grandson Caius, the sole surviving son of Germanicus, better known by his childhood name of Caligula, acquired in the camps on the Rhine, and his grandson by birth, Tiberius Gemellus. Upon Caius, the elder of the two, then twenty-five years of age, the Senate immediately conferred the powers of the principate. The resentment of the senators towards his predecessor found vent in refusing him the posthumous honor of deification. Caius adopted his cousin, but within a year had him put to death.