The Histories

“Caesar” and “Augustus” were Roman titles, the former of which was based off the dictator Julius Caesar and the latter a title given to Octavian (the first Roman emperor), meaning “revered.” The title “Augustus” was subsequently used to denote a Roman emperor, while “Caesar” was a junior rank given to heirs.

The cursus honorum, meaning “course of honors” in Latin, was the Roman term for the sequential order of public offices held by aspiring politicians in Rome. Men of the Senatorial rank had a set career path, in which they would serve in the military for roughly 10 years as a young man and then become a Questor (a public official with varied responsibilities), an Aedile, and so on until they reached higher ranks such as consuls. During the Principate, the cursus honorum underwent changes as power was concentrated in the hands of the emperor, removing the responsibilities of some roles and making imperial favor important in success. Tacitus references the cursus honorum to describe the career progression of several individuals, occasionally criticizing people who did not earn the ranks they had, such as Vitellius.

A legion was the largest military unit of the Roman army, consisting of around 4,500-6,000 soldiers. Each legion was a self-sufficient fighting force composed of legionaries (Roman citizens acting as heavy infantry), cavalry, and auxiliary soldiers. Legions were stationed across the empire, with most concentrated on vulnerable borders. By the last phase of the Roman Republic, legions were often more loyal to their commanders than to the Roman state at large, allowing for commanders to start civil wars. This process continued throughout the empire. Tacitus shows that the personal loyalties of each legion varied, as did their concerns. Who a legion supported became very important in the turbulent year of 69 CE.

The Praetorian Guard was a military unit established by Emperor Augustus with the task of protecting the emperor and his family. In due time, they became an important force in deciding imperial succession because they were often the only armed unit in the vicinity of Rome. Emperors would bribe them in order to secure their loyalty because if this was lost, they were unlikely to keep the throne for long. The Praetorian Guard played a key role in the overthrow of Galba and then remained remarkably loyal to Otho, even joining Vespasian after Otho’s death to get revenge.

“Principate” is a term derived from the word “princeps,” meaning first citizen. Augustus adopted this title to convey his position within the state while avoiding the politically charged term “king.” The word “Principate” has since been used by historians to denote the period of Roman history after 27 BCE, separating it from the republican period in which the Senate was the primary authority.