What it is
The Histories (Historiae) is Tacitus's account of the Roman world from the civil wars of 69 CE — the "year of the four emperors" — through the Flavian dynasty to the death of Domitian in 96. Written before the Annals though covering the later period, it originally ran to perhaps twelve or fourteen books. Only the first four and part of the fifth survive, carrying the narrative through 69 and into 70 CE: the fall of Galba, the brief reigns of Otho and Vitellius, and the triumph of Vespasian. The surviving portion is the most detailed account of a Roman civil war that antiquity has left us.
Historical context
The death of Nero in 68 had ended the Julio-Claudian line and, with it, the fiction that the Principate was the property of a single family with a claim by descent from Augustus. What followed was a scramble for the purple decided by the legions. Tacitus, who had lived through the Flavian period and risen under it, wrote with the authority of a man describing the recent past of his own class.
What it argues
The Histories contains Tacitus's most cited political observation: that the year 69 revealed a secret of empire (arcanum imperii) — that an emperor could be made somewhere other than Rome, by armies on the frontier rather than by the senate in the city. The sentence names the structural fault the platform's army-and-state theme reads across the whole imperial period: once the legions understood that they, and not the constitution, decided the succession, no settlement of the throne was ever again fully secure. The civil war of 69 was the first demonstration; the third-century crisis was the same fault running unchecked.
The surviving books are also a masterclass in the dynamics of collapse — the breakdown of discipline, the contagion of rumour, the way ordinary men are swept into atrocity. The fifth book opens the account of the Jewish War and Titus's siege of Jerusalem, and contains Tacitus's hostile and influential excursus on the Jews — a passage the platform notes for its later misuse, as with the ethnographic material of the Germania.
Reception and influence
Read alongside the Annals as the second pillar of Tacitean political analysis, the Histories shaped the early-modern literature on civil war, faction and the fragility of legitimacy. Its diagnosis of the army as the true electorate of the empire is the starting point for every serious account of why the Roman monarchy never solved the succession problem.
Citing the Histories
Standard citation is by book and chapter (e.g. Hist. 1.4 for the arcanum imperii). The Latin text is in the Oxford Classical Texts; Damon's edition is the standard English aid. Cite Tacitus's Histories as distinct from Polybius's earlier Greek Histories. See our Sources page.