Content Warning: This section includes descriptions of warfare and attacks against civilians; mentions of sexual violence, suicide, and enslavement; and an antisemitic description of Jewish history and culture.

A central aspect of The Histories is Tacitus’s warnings about how power damages moral character. Power, Tacitus argues, has the worst influence on those who are already immoral, but some, like Antonius Primus, “needed success” to show their true character (153). Moreover, as Tacitus has Galba warn Piso, power attracts sycophants who will “weaken” the character of those who were previously good (12).

The corruption of figures once they achieve power is common within The Histories, but its most notable examples are in the Vitellians following their victory over the Othonians and then the Flavian army in Italy following their victory over the Vitellians. In both examples, Tacitus also shows how corruption among the leaders of a group has a trickle-down impact that leads to their army being corrupted in turn. With the Vitellians, Vitellius himself is consistently presented as ill-suited to rule. During the opening stages of the rebellion, he acted lazy and without the speed that Tacitus claims is essential to success in a civil war. His imperial challenge only succeeded because of the eagerness of his army and the talent of his generals.