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

“The story which I am approaching is rich with disasters, grimly marked with battles, rent by treason and savage even in peacetime. Four emperors perished violently. There were three civil wars, still more foreign campaigns, and often conflicts which combined elements of both.”

In the opening chapters of The Histories, Tacitus emphasizes the civil wars, setting the stage for his focus on this and hinting at the rapid succession of leaders that will occur within the narrative. The four emperors who died violently are Galba, Otho, Vitellius, and Domitian (though this is not covered in the surviving parts of the book).

“A well-hidden secret of the principate had been revealed: it was possible, it seemed, for an emperor to be chosen outside Rome.”

The reveal of this “secret” is presented by Tacitus as a key factor that contributed to the chaos in Rome in 69 CE. The lack of central authority allowed provincial leaders to rebel against Rome and try to become emperor, as Galba had. Galba’s precedent demonstrated the possibility of success to Vitellius and Vespasian.

“A substitute for freedom will be that our emperors are starting to be selected. Now that the dynasty of the Julii and Claudii has come to an end, the process of adoption will find the best man for the job.”

Tacitus has Galba make a speech on the need for adoption, through which he seeks to draw a comparison between the situation he describes and the later adoption of Trajan by Nerva. Tacitus expresses the view that an emperor is needed because of the size of the empire and that the lack of liberty must be compensated for by good rule, ensured through adoption. However, as shown by the failure of Piso to secure Galba’s dynasty, it is critical that the adoption is of the right man.