I realise that this is a fairly broad question, but I am trying to get a sense of the ratio between the total population and the size of the military that societies could support at different times and places throughout European history. My main interest would be comparing ancient Rome to dark ages Britain and Scandinavia (Vikings) and then to medieval and late medieval Britain and France. I'd be interested in how the social structure and economic setup of different societies effects the 'efficiency' through which they are able to support the largest military for a given population size.

  • This is very broad. Just Roman military strength across the centuries deserves its own book. How about asking about each period/region combination in separate questions?
    – Semaphore
    Commented Mar 19, 2015 at 2:41
  • I agree that it's very broad. I guess I couldn't expect a deep answer, but perhaps this can be answered by just touching on the most important aspects or pivotal social/economic/technological advances? Commented Mar 19, 2015 at 2:56
  • Are you asking for the actual military/population ratios, or an examination of the "pivotal social/economic/technological advances" behind the changes to military strength from Ancient Rome to Medieval Europe? The latter is a possible duplicate of: history.stackexchange.com/questions/19098/…
    – Semaphore
    Commented Mar 19, 2015 at 3:26
  • 1
    The best military is not always the biggest, it depends on the technology of the time. In the Bronze Age armies were small because military technology (using bronze) was very expensive based on rarity of supply. Once iron had been developed, the ore for which was readily available, armies became much larger because it was relatively cheap to manufacture arms.
    – scoobydoo
    Commented Mar 19, 2015 at 7:13
  • You may find existing answers to your overall question in relation to the Napoleonic wars. Revolutionary France raised armies in very great numbers and was able to defeat other European armies (for some time).
    – Drux
    Commented Mar 19, 2015 at 8:33

2 Answers 2


Extremely rough approximates guestimates

Ancient times 1%. Industrial 10% Industrial-Crisis maximum - 20%

20% is around ALL the military age males. Ancient period that gives 1 military age male in 20.

  • This is FULL Time military, obviously more can be supported as a part time militia.
    – pugsville
    Commented Mar 19, 2015 at 3:16
  • But what about dark ages and medieval like the question asked?
    – user5001
    Commented Mar 19, 2015 at 5:17
  • To continue with this line of approximates/guestimates into medieval times: 3 classes, one of them "soldiers" ... 33% ... problem solved ... :)
    – Drux
    Commented Mar 19, 2015 at 8:46
  • Note that nomadic peoples such as the Mongols, Huns and Tartars also approach close to 20%, which along with their better overall health (and often larger physical body size) compared to historical agrarian societies explains much of how they were so frequently able to topple empires - when they united under a strong leader. Commented Mar 20, 2015 at 0:23

You may want to look up the work of Andreski, in particular his book on this very topic.

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