Hi Justin
What about senior officers, like legates? These were generally career soldiers, right? Your reference about the tribunes suggests that only two of the tribunes were career climbers from Rome.
I guess what I'm saying is I know almost nothing about it. Caesar's legates, like Antony and Labienus, seemed to be professional soldiers instead of politicians (and Antony flopped at politics when he tried to play Triumvir with Augustus).
-Tim
Birth class status was the primary determiner of where one would be placed in Rome's military. Non-citizens would go to the auxiliaries, although citizens could enlist in the auxiliaries as well. Some citizens, in fact, did this, as the enlistment term was shorter, it was arguably less dangerous, and the location would be arguably more permanent. Of course status, pay, bonuses, and land grants were less too. The exception to this was the auxiliary cavalry which was arguably more prestigious and possibly paid the same or even more than the legions. (Scholars don't know for certain yet on what exact scale all the different units were paid at, and the cavalry in a mixed infantry and cavalry cohort would probably be paid less than the cavalry in a pure cavalry cohort.)
Citizens would go to the legions, but if Rome really needed to raise a legion quickly and badly and the man was a good prospect, a non-citizen might immediately be granted citizenship so that he could go into the legions. (Julius Caesar did this with the Spanish.) Average citizen soldiers could move up through the lower non-commissioned ranks to become centurions, then the top centurion in a cohort, then a centurion in the first cohort, then the first centurion of the first cohort, then the legionary camp prefect. (A soldier's chances of even making centurion, however, were quite slim.) The legionary camp prefect, although technically ranking third militarily and eighth socially in the legion, would actually be the most experienced and respected man in the entire legion due to his lifetime of experience and humble soldier's roots, which the men of the legion could more readily identify with compared to the wealthy and elite tribunes and legate.
The two types of legionary tribunes generally had two different career paths due to their birth class status. The Tribunes Agusticlavii, of which there were theoretically five in a legion, were basically the experienced career officers and could serve indefinitely. They could be in their early twenties on up in age. They were called this (narrow stripe tribunes) because they were entitled to wear narrow purple stripes on their white tunics and a gold ring to signify their Equestrian class status. Equestrians, if they were fortunate, would usually begin their military careers as prefects of infantry auxiliary cohorts. From there they might be promoted to being prefect of a mixed infantry and cavalry cohort. They then might be promoted to become a legionary tribune. From there they might be promoted to be prefect of a cavalry auxiliary cohort or prefect of a Praetorian cohort. Of course all of this depended upon how good one was, what one's personal preference was, how ambitious one was, and, most importantly, how wealthy and well-connected one was. Due to the last of these reasons, however, an Equestrian might not be able to start his career as a prefect of an infantry auxiliary cohort. Instead, he might have to start as a centurion in a legion or an auxiliary cohort or, in the worst case, as a normal legionary.
The Tribunes Laticlavii (broad stripe tribunes) were in their late teens or early twenties and wore broad purple stripes on their white tunics and, at least traditionally, an iron ring to signify their Patrician class. There were theoretically only one to a legion and he technically ranked second, after the legate, both militarily and socially, but due to his youth and inexperience would or should defer battlefield decisions to the Tribunes Agusticlavii and the legionary camp prefect. He was basically with the legion for a year or two to learn the ropes, as this was the first stage in his military and political career. (These were intertwined, for Rome was foremost a military society.) From the legion, he would transfer to any number of civilian posts and after these civilian posts, he might return as a Legate. Legates were usually at least 30 years old and theoretically served for three years, but some served for less if they were terribly incompetent, or much longer if they were needed or if they were effective and wanted to. One must remember that battlefield spoils, usually in the form of slaves, could be quite profitable. (Julius Caesar was a broke patrician who owed money to everyone, but his military activities made him a very rich man.)
Of course much of the above regarding the tribunes is "theoretically" speaking. In reality, one could think of Tribunes, either broad or narrow striped, as today's vice presidents in a company. Technically a company, like a Roman Legion, might only require a certain number of competent vice presidents, but if the president, board members, significant stock holders, etc. wish to help out their family, friends, supporters, etc., a company might have a multitude of superfluous vice presidents. As the Empire progressed and the equestrian and patrician ranks swelled, room had to be made for these men, so a legion might very well have ten Tribunes Laticlavii and ten Tribunes Agusticlavii! One must remember that, unlike most countries today, Rome was a military society and the military was, for the patricians and equestrians, the only suitable profession with which to begin a respectable career. All civil positions required military experience. Of course good soldiers don't necessarily make good politicians, and good politicians don't necessarily make good soldiers.
