I’m assuming there was a glass ceiling you could not move beyond unless you were noble born, but within the social mobility limits of ancient organizations like the military or governmental bureaucracy in ancient Rome or Egypt how did a man advance in his career?
I’m assuming the bosses did not want incompetents running things so there were some elements of meritocracy. Is there any historical record of how people were chosen for advancement?
My guess is that there was no particular general rule to this, just as there is no particular general rule now. It will vary from organization to organization, and even from particular circumstance to particular circumstance, just like now.
The Imperial Roman Army, from the end of the Republic to the fall of the Western Empire, was a volunteer force of career soldiers, mostly drawn from the provinces. Centurions were promoted from the ranks, and rose in rank based on a combination of seniority, merit, and politics. The highest of these were promoted to the equestrian class, an aristocracy below the senatorial class. Senior officers were always of at least equestrian class, and were mostly Italian aristocrats, plus a few of the most talented of the professional soldiers. Romans of high rank were expected to lead in battle as well as in politics, although they relied more heavily on professional officers and advisers than in the days of the Republic, and were appointed for brief periods during their rotation through the cursus honorum. Toward the end of the Empire, this pretense of military command was almost entirely abandoned, and professional officers became the rule.
I can’t say for sure, but I’d imagine seniority would be the biggest factor, but based on Vegetius, martial and organisational prowess was also essential for promotion at the lower ranks of officer. Being the first guy over a wall or to recover the enemy standard would definitely get you a large promotion.
There would also be a personal politics component, as centurions chose their own optios, who were more likely to become centurions themselves, so being a suck-up might have paid off.
ETA: re-enlisting after the first tour (20 years!) could also have a big pay-off.
In the late republic and Roman Empire the glass ceiling would have been wealth not nobility. There are many examples of “new men”, becoming prominent in Rome, scorned by the older Senatorial families but still achieving a lot of fame and high rank.
Gaius Marius being one of the most famous (and 7 times Consul of Rome).
He was born of the Equestrian order which is lower aristocracy, but entry into the Equestrians was by wealth, not just birth.
I remember a phrase uttered in some work where a wealthy landed member of the gentry referred to another person in a snide manner using the word ‘equestrian’.
As an insult, it didn’t make sense to me at the time.
Now, it does.
Thanks ever so much.
Yep, the snark of “new money” vs “old money” goes back at least 2200 years, probably more. Keep in mind by the time of the empire, some of the Patrician Senatorial families had been wealthy for 600 years, makes modern “old money” look positively adolescent.
See, nowadays a boring unimportant person would be “pedestrian”.
In Ben Hur, Heston gets his 'foot in the door" by rescuing the big shot Roman. I recall reading a lot of “adoptions” of adults, which I ssume consists of welcoming the fellow into your household, designating him heir, etc. This was probably based on recognition of merit (or brown-nosing) and thus helping the person. As also mentioned, being prominent in winning a battle also helped.
Makes some countries look positively neonate 
Yep: Germany is barely a blip on a timescale that long.
This was true in Japanese Bushido culture too, IIRC. Heirless nobility would sometimes adopt unrelated but worthy adult males.