son of Germanicus, though in 21 A.D. he was only fourteen years old, in order that he might in time be made the rival of Tiberius.  The latter, indeed, tried at first to moderate the charges of high treason, his supreme defense; he feigned that he did not know or did not see many things, and instead of resisting, he began to make long sojourns away from Rome, thus turning over the capital, in which the pretorian guard remained, to the calumnies of his enemies.  Of all these enemies the most terrible was Agrippina, who, passionate, vehement, without judgment, abused in good faith both the relationship which protected her and the pity which her misfortune had aroused.  She allowed no occasion for taunting Tiberius with his pretended crime to escape her, using to this end not only words, but scenes and actions, which impressed the public even more strongly than open accusations could have done.  A supper to which Tiberius had invited her became famous at Rome, for at it she refused obstinately and ostentatiously to touch any food or drink whatever, to the astonishment of the guests, who understood perfectly what her gestures meant.  And such calumnies and such affronts Tiberius answered only with a weary and disdainful inertia; at most, when his patience was exhausted, some bitter and concise reproof would escape him.

I have no doubt that Tiberius had resolved at the beginning to avoid all harsh measures as far as possible; for unpopular, misunderstood, and detested as he was, he did not dare to use violence against a large part of the aristocracy and against his own house.  Furthermore, Agrippina was the least intelligent of the women of the family, and her senseless opposition could be tolerated as long as Livia and Antonia, the two really serious ladies of the family, sided with Tiberius.  But it is easy to understand that this situation could not long endure.  A power which defends itself weakly against the attacks of its enemies is destined to sink rapidly into a decline, and the party of Agrippina would therefore quickly have gained favor and power had there not arisen, to sustain the vacillating strength of Tiberius, a man whose name was to become sadly famous—­Sejanus—­the commander of the pretorian guard.

Sejanus belonged to an obscure family of knights—­to what we should now call the bourgeoisie.  He was not a senator, and he held no great political position; for his charge as commander of the guard was a purely military office.  In ordinary times he would have remained a secondary personage, exclusively concerned with the exacting duties of his command; but the party of Agrippina with its intrigues, and the weakness and uncertainty of Tiberius, made of him, however, for a certain time, a formidable power.  It is not difficult to see whence this power arose.  The loyalty of the pretorian guard, upon which depended the security and the safety of the imperial authority, was one of the things which must seriously have preoccupied