Troop to Population Ratio

Skip.knox hits the main points right on the head. Standing armies are a very rare occurance in history, and were only common in certain periods.

However the proportion can be all over the map depending on how your economy runs, ideas of citizenship etc. Lots of flexibility to work with. Consider the Spartans for instance.

 

Sparta is a good example of an autocratic society, where basically every male citizen must do an extended military service and protect the city when war arises.

In North Korea, the military personnel represents 48% of the active population (not sure what that means over there, but hey...). Sure, it's not a... common repartition, but it basically proves that it can be any number you want provided you give an explanation of how your society works considering half its citizens are warmongering.

In my WIP, I have a very autocratic society, where every one must serve in the army at least 4 months per year. The rest of the time they can work in whatever branch they may chose, and thus, support the national economy.

 

So much of it is also driven by economics.

In Sparta the soldiers are supported by a large slave population who do the more productive work.

One of the big questions has to be how expensive are your troops? If might take say 50 workers or more to support a knight and a couple of war horses, while if you rely on self-armed militia, things can be really cheap.

 

2-4% of the populace in military service is very, very high. Something you'd find only if the society was militarized to start with, or planning a military adventure.

More realistic scenario: A few thousand knights or equivalent, aristocratic, trained in arms.

For each knight, a sergeant or three and a few dozen professional soldiers. Situation you describe, mostly charged with putting down bandits or petty border disputes.

Below them, a militia, strictly part time, training a few days each month. Rest of the time they're tradesmen or farmers or whatever.

Time of crisis the professional soldiers - especially the sergeants - step in and drill the militia into semi-professional companies, acting as officers and backbone. Best militiamen get to become pro's.


Getting called up happens if a border dispute becomes hot, or if there is a peasant rebellion of some sort (a depressingly common situation in feudal societies - lots of unhappy folks at the bottom).

To justify the numbers you want, I'd suggest a fairly recent, really major peasant uprising, one that *really* spooked those at the top of the heap (as in lots of dead top ranked nobles). Fearing a second revolt, and unwilling to institute true reforms, they opted to keep the militia in full time service at hellish expense rather than letting its members go back to civilian status.

If the revolt was big enough to cross national borders, that could account for two or three countries having armies at the specified levels.

Additional note: Going to be a lot of spy's and heavy handed inquisitors running around, searching for escaped or potential rebels. Repeated rumors that some of the top peasant rebel leaders escaped should be rampant.

 

The other way you can increase the ratio of military to civilians is to change technology so the military is either cheaper, or the support industries more efficient.

So if metalworking or armoring becomes cheaper than it is easier to support an armoured knight. If you change the system from one of personal squiring, to schools, where one veteran knight and a couple of sergeants are training 50 new potential knights, that makes it cheaper as well.

Throw in some crops, or agricultural techniques that are more efficient (remember the switch from the two field to three field system), or a plant that reduces illness or increases production of livestock and voila...you can have a culture that is able to support a larger military.

 

Cannons are a fascinating piece of technology to consider for the battlefield. Traditionally the two great factors in a battle are "fire and movement" and canons are quite good at one, but very poor at the other. Lots of great stuff to play with in your story there.

 

Honestly, I think the populations are a bit on the small side. When you say three countries to a continent, which I'm presuming is going to be roughly Europe sized (quite a small continent, relatively speaking), and each country has 300k people in it? Less than a million in total.

That's VERY small, for a continent of relatively hospitable habitation, especially if these are people with a tech level of around cannon manufacturing (here I'm thinking as in the classical napoleon era type of cannon, which requires big foundries of a relatively high, regulated quality to operate, similar gunpowder manufacturing capabilities, and relatively advanced supply and logistics).

Europe pre-black death had a pop of anywhere up to 150 million. During the industrial revolution that skyrocketed. And if you want big armies, several % of the pop or more and to be able to keep them feed and supplied, you're going to need to have some sort of agricultural revolution having taken places, providing enough food and freeing up enough people for factory work and army duty.

In my own world, the main culture I focus on, the Isle Born, keep standing armies. This stems from a long raiding tradition and isn't central - each Fang-Thane supports his own, significantly smaller force that are all combined in times of war under the countries Lord. For the biggest county, Ilaerin, this comprises about 48,000 people out of a pop of 1.2 mil. This is possible, I feel, because I have mixed gender armies, and much like the Roman army, the Fang-Thanes use their soldiers in public service roles, such as building roads and bridges and helping with the harvest.

Hope this helps - but great premise, you can write some real interesting battles with armies tied to defensive positions with their canon and more flexible armies - maybe the other countries start to fight in looser formation and use more ranged weapons - longbows, crossbows, even slings to engage the enemy without being exposed to heavy shot or canister fire??