Before we dive in, we should stop to clarify some of our key actors here, the Roman magistrates and officers with a role in all of this. A Roman army consisted of one or more legions, supported by a number (usually two) alae recruited from Rome’s Italian allies, the socii. Legions in the Republic did not have specific commanders, rather the whole army was commanded by a single magistrate with imperium (the power to command armies and organize courts). That magistrate was usually a consul (of which there were two every year), but praetors and dictators,1 all had imperium and so might lead an army. Generally the consuls lead the main two armies. When more commanders were needed, former consuls and praetors might be delegated the job as a stand-in for the current magistrates, these were called pro-consuls and pro-praetors (or collectively, “pro-magistrates”) and they had imperium too.
In addition to the imperium-haver leading the army, there were also a set of staff officers called military tribunes, important to the process. These fellows don’t have command of a specific part of the legion, but are “officers without portfolio”, handling whatever the imperium-haver wants handled; at times they may have command of part of a legion or all of one legion. Finally, there’s one more major magistrate in the army: the quaestor. A much more junior magistrate than the imperium-haver (but senior to the tribunes), he handles pay and probably in this period also supply. That said, the quaestor is not usually the general’s “number two” even though it seems like he might be; quaestors are quite junior magistrates and the imperium-haver has probably brought friends or advisors with a lot more experience than his quaestor (who may or may not be someone the imperium-haver knows or likes). […]
The first thing to note about this process, before we even start is that the dilectus was a regular process which happened every year at a regular time. The Romans did have a system to rapidly raise new troops in an emergency (it was called a tumultus), where the main officials, the consuls, could just grab any citizen into their army in a major emergency. But emergencies like that were very rare; for the most part the Roman army was filled out by the regular process of the dilectus, which happened annually in tune with Rome’s political calendar. That regularity is going to be important to understand how this process is able to move so many people around: because it is regular, people could adapt their schedules and make provisions for a process that happened every year. I should note the dilectus could also be held out of season, though often the times we hear about this it is because it went poorly (e.g. in 275 BC, no one shows up).
The process really begins with the consular elections for the year, which bounced around a little in the calendar but generally happened around September,2 though the consuls do not take office until the start of the next calendar year. As we’ve discussed, the year originally seems to have started in March (and so consuls were inaugurated then), but in 153 was shifted to January (and so consuls were inaugurated then).
What’s really clear is that there is some standard business that happens as the year turns over every year in the Middle Republic and we can see this in the way that Livy structures his history, with year-breaks signaled by these events: the inauguration of new consuls, the assignment of senior Roman magistrates and pro-magistrates to provinces, and the determinations of how forces will be allotted between those provinces. And that sequence makes a lot of sense: once the Senate knows who has been elected, it can assign provinces to them for the coming year (the law requiring Senate province assignments to be blind to who was elected, the lex Sempronia de provinciis consularibus, was only passed in 123) and then allocate troops to them. That allocation (which also, by the by, includes redirecting food supplies from one theater to another, as Rome is often militarily actively in multiple places) includes both existing formations, but is also going to include the raising of new legions or the conscription of new troops to fill out existing legions, a practice Livy notes.
The consuls, now inaugurated have another key task before they can embark on the dilectus, which is the selection of military tribunes, a set of staff officers who assist the consuls and other magistrates leading armies. There are six military tribunes per legion (so 24 in a normal year where each consul enrolls two legions); by this point four are elected and two are appointed by the consul. The military tribunes themselves seem to have often been a mix, some of them being relatively inexperienced aristocrats doing their military service in the most prestigious way possible and getting command experience, while Polybius also notes that some military tribunes were required to have already had a decade in the ranks when selected (Polyb. 6.19.1). These fellows have to be selected first because they clearly matter for the process as it goes forward.
The end of this process, which as we’ll see takes place over several days at least, though exactly how many is unclear, will have have had to have taken place in or before March, the Roman month of Martius, which opened the normal campaigning season with a bunch of festivals on the Kalends (the first day of the month) to Mars. As Rome’s wars grew more distant and its domestic affairs more complex, it’s not surprising that the Romans opted to shift where the year began on the calendar to give the new consuls a bit more of winter to work with before they would be departing Rome with their armies. It should be noted that while Roman warfare was seasonal, it was only weakly so: Roman armies stayed deployed all year round in the Middle Republic, but serious operations generally waited until spring when forage and fodder would be more available.
That in turn also means that the dilectus is taking place in winter, which also matters for understanding the process: this is a low-ebb in the labor demands in the agricultural calendar. I find it striking that Rome’s elections happen in late summer or early fall, when it would actually be rather inconvenient for poor Romans to spend a day voting (it’s the planting season), but the dilectus is placed over winter where it would be far easier to get everyone to show up. I doubt this contrast was accidental; the Roman election system is quite intentionally designed to preference the votes of wealthier Romans in quite a few ways.
So before the dilectus begins, we have our regular sequence: the consuls are inaugurated at the beginning of the year, the Senate meets and assigns provinces and sets military priorities, including how many soldiers are to be enrolled. The Senate’s advice is not technically legally binding, but in this period is almost always obeyed. Military tribunes are selected (some by election, some by appointment) and at last the consuls can announce the day of the dilectus, conveniently now falling in the first couple of months of the year when the demand for agricultural labor is low and thus everyone, in theory, can afford to show up for the selection process.
Bret Devereaux, “Collections: How To Raise a Roman Army: The Dilectus“, A Collection of Unmitigated Pedantry, 2023-06-16.
1. And the dictator’s master of the horse.
2. On this, see J.T. Ramsey, “The Date of the Consular Elections in 63 and the Inception of Catiline’s Conspiracy”, HSCP 110 (2019): 213-270.
