Regarding the percentage of soldiers under arms, how do historians reconcile the low populations of certain countries with the amount of soldiers supposedly present at battles? For example, Scotland likely had a population just under a million in the 1500s, yet were supposedly able to field 30/40,000 men at Flodden, which would suggest a population that they wouldn’t achieve until the modern era.

I wrote a long post about this which just got eaten by a browser crash, so I’m a bit annoyed. Premodern MPR statistics are not comprehensive, ultimately estimates based on how much you trust partial, sometimes noncontemporary, and often biased sources.

However, the stuff I just read suggested that premodern MPR was at its lowest in the 12th century, highest in the 17th century, and even then rates of 1.7% (in France under Louis XIV) or 3% (in Sweden in the 17th century) were quite astonishing compared to the norm. 

So Flodden…could be the sources are wrong, could be the Scots hired a bunch of mercenaries, could be that 30,000 men represented a sudden intense mobilization of every able-bodied man as opposed to the number of men who could be normally trained and equipped for war as professionals.