The difference is that early modern armies stressed far more on mercenary and standing forces.They are far more expensive to maintain.In regards to medieval armies,the problem is that city-states of the antiquity most likely have a greater percentage of freemen than the Middle Ages despite the presence of slaves.Citizens were fully expected to be able to fight, and most likely did have some form of military training since childhood.The problem with the Middle Ages was that the bulk of the population consisted of serfs and that the population relied on the lord to provide protection in exchange for providing tax revenues.Most of the serfs simply do not fight,nor are they trained to.
Not necessarily. The Sassanid empire had standing armies in late antiquity and large noble houses. Of these, traditionally, armies only were 12,000 in number! The above posters are suggesting seriously that the city state of Athens alone can produce an army in excess of Sassanid field armies! Why would Rome even bother with the Sassanids and Arsacids, when they can easily dig deep and levy 120k warriors from Greece in a few months and conquer Iran whom with only 120k soldiers would overwhelm totally numerically. So much for Rome, they must have been quite incompetent!
Rome itself must be questioned as a ridiculous entity. It possessed around 400-500k warriors in the era of Mare Nostrum. This out of 50 million inhabitants of the empire, is approximately .009% of the population! Yet small Greek city states are able to levy 10% of their population for armies of 15k (even assuming Athens had a population of 150,000, which is silly, considering that a huge amount of these were slaves, women and children; I suppose Athens had access to some sort of Soviet era mass conscription mechanism). Returning to Rome, if they had this skill to recruit such large numbers in Italy, why did they not do so and stop posturing as having issues protecting their borders? It seems nearly comical, that Rome is having issues protecting their borders when they could just levy 10% of their population and gather 5 million warriors to guard every single fortress with 100k soldiers.
Achaemenid statistics do not work either. If we assume 49 million population at their height, an army of 2 million would comprise 4% of the total empire. Is anyone of the opinion that a massive polyglot empire, ruled by a minority of Elamo-Persians who experience frequent satrap revolts, is able to conscript 4% of their entire population? If I am not mistaken either, this would be that 2% of the world (which I do not buy that the empire possessed this much percentage of the world population) population was levied to invade Greece alone! Assyria, an empire with greater militarist focus and similar population was only able to levy 90k warriors in a population of some 11 million at least, comprising an estimated .008% of the populace. If your view is that the Elamites-Persians were that superior in conscriptions than the greatest military power of the ancient near east, then there is nothing more to say.
This is all simply estimates of populaces. We know most of these societies were unaware of even their total populaces. If a civilization lacks the ability to levy even income taxes or have census data, how can they feasibly collect 4% of the population for war? A major difference, for some states, such as Assyria, we have records of their soldier numbers that were not of a history account, but rather hard data found within ruins. So, we are comparing fanciful claims of historians that reported every even he heard through narration against hard datas? Even if we accept the data as
@Fabius Maximus does, you then have to trust the conception that the Elamo-Persians were vastly superior in troop collection as Assyria. For instance, if the Elamo-Persians collected .008% of their population, their army would be in total 392k soldiers approximately. At Roman levels, it would be 442k soldiers.
@dandan_noodles You seem to be switching the goal post. We know steppe empires could levy larger percentages of their populace than most peoples. We also understand that a host of migratory people can unleash large numbers in an instant. However, to assume these practices existed in the Achaemenid empire or Rome to any serious degree, is not reasonable. Assyria also levied soldiers essentially every year to invade peoples in the old and Middle Kingdoms, yet do we believe that every free man in Assyria legitimately campaigned every year?
Even in China, most battles in the 7th century under the Tang have less than 80k soldiers combatting. At Suiyang, the combat over this location lasted a year and the Yan forces sent 100k over an entire year to take the location! In the wars in Korea, the Tang armies are less than 40k always and the Koreans vary and are always below 50k. At Talas, the Anxi protectorate arrived with no more than 25k warriors. Is the opinion of the opposing posters, that Greek city states could levy greater numbers of soldiers than the Tang Dynasty!?