My extent of knowledge of the Praetorian Guard was that they were a kind of personal army of the emperor, but spent more time murdering him than actually protecting him.
So how would a Praetorian compare, on average, in skill and equipment to a legionnaire serving in a campaign or on a frontier, we'll say 10 years into service.
This is based on reading Gibbon and refreshing my mind from a wiki page. The answer: it varied through different points of Rome's history.
The praetorian guard was established by Octavian and originally was mostly not stationed in Rome. This was changed under Tiberius when they built a large fort just outside Rome. This made them very politically powerful - as the Emperor and the city of Rome were pretty much at their mercy. At this point they were quite capable troops comparable to legionaries. The guard was composed of legionaries recruited in Italy.
Over time they became rather decadent and spoiled and demanded liberal "donatives" from Emperors on their ascent. This reached its height when unsatisfied with their gifts after the assassination of Commodus and the ascension of Pertinax a group killed the Emperor and then sold the title to a man named Julianus.
Understandably Romans everwhere were a little miffed by this. A general by the name of Septimius Severus marched on Rome. The Praetorian guard by this time weren't really keen on fighting, and were a little alarmed when they suddenly had to start drilling again. In the end they didn't even offer battle: the conspirators responsible for the death of Pertinax were turned over and the rest of the guard was banished.
At this point Septimius Severus decided to make the guard larger and populate it with his own veteran and loyal troops. He also set up a system where praetorian soldiers would be recruited from capable veterans in the provinces. My impression is by this time the inhabitants of Italy had become fairly urban and lost a large portion of their martial virtue.
Once the recruitment began from provincial veterans the guard became extremely capable once again.
Over time the guard declined in importance though as Rome became less important to the Roman Empire (e.g. during the time of Diocletian it was not even an administrative center) and was functionally replaced by similar units which acompanied the Emperors.
Additional:
Was the Praetorian Guard an elite division in the army, sort of like the Navy SEALs are to the Navy? Or was the Praetorian Guard a separate faction?
/u/McGuineaRI gave a pretty good answer to your question.
But something important to remember is that combat in the ancient world often did not look quite like it's portrayed in movies. There've been two good askhistorians threads on this in the past month or so.
historically how much did martial skill matter in combat
and
The short version of all of this is that infantry combat in the ancient world (and to some extent almost up to the modern age) relied on massed formations of men.
The Roman legions were far more flexible than the phalanx based formations of their predecessors but conceptually they were not all that different. A line of men, stacked four to seven deep, each carrying a large rectangular shield and a short sword. (And Pilum or throwing spears as well). They hold the shield in the left and a sword in the right. Your shield protects your own torso and a portion of the man to your left next to you. An individual relies on the men behind him and to his side to protect his sides. A legionaire leads with his shield and thrusts with his sword.
In combat, two units of men would collide, and disciplined soldiers would retain formation. The formation protects men from being stabbed from behind, and allows them to protect themselves. The side to lose is the first side to break and run. Once they break and run, they are pursued and killed. Infantry could certainly do this, but this was a common use for cavalry.
As specially chosen legionaires, Praetorians may well have been physically larger and more imposing than the average legionaire. However, this does not necessarily translate to them being skilled in individual combat, because the roman legion system of fighting did not really emphasize one on one combat.
Does anyone have a rough idea (ballpark number) of the number of Praetorians at any given time?
I'm sure it fluctuated, but I realize I don't really know how many soldiers were in the guard. I always assumed less than a legion.
Anyone know?
I'm not sure when in Rome's history this might have been but I heard that the Praetorian Guard were actually chosen more for how they looked than skill. Even things like how rounded their ankles are.
Can anyone confirm whether any of this is true?
Was there a deterioration in the actual quality of the troops in the Praetorian Guard over time?