Sorry if this is the wrong place, but Are there any good resources or estimates for the maximum army sizes that could be levied by kingdoms or nations in medieval times, if only based on modern estimated without primary sources? Examples such as:
- 13th century HRE.
- 11-13th century Japan.
- Any point in China's medieval history?
- The various Italian city states.
- The kingdom of England before the Norman conquest.
Of course, I am talking about the entire state armies, not just the forces for one battle.
The problem with 'entire state armies' is that a state didn't send all its forces to a battle...ever. They had castles that needed garrisoned. Cities and homes guarded. They could also raise and train forces in months if necessary through levies. A comparatively small force was sent out to open battle or to invade another country.
However, here are my current guesses. Regarding to 11th-13th century HRE, Emperor Frederick I in his conflicts with the Italian city states nominally under his control led a force of 8,000 knights to northern Italy during his Fifth Italian Campaign. He did not receive assistance from Henry the Lion, who was duke of both Bavaria and Saxony. He also received later reinforcements of around 2,000 from Germany. So for an invasion of Italy, he marshaled roughly 10,000 Germans. Now if Henry had helped you might have seen another 5,000. So 15,000 for an invasion out of Germany, but for fighting in Germany it wouldn't be impossible to see three or four times that number being organized for local campaigns. Emperor also wasn't a total ruler, so you might have seen more German lords refusing to contribute to Frederick's campaign. So I'd estimate 50,000-60,000
total for Germany of this period but a more active force of 15,000-20,000. This fits with the forces Frederick supposedly led on the Third Crusade. Exaggerated forces claimed 100,000 men, with 20,000 knights, but scholars mostly agree on 15,000, with 3,000 knights.
The HRE during Frederick II's time is even more difficult to judge, since he was also King of Sicily and Sicily could raise something like 7,000-10,000 for Italian campaigns. Frederick II also favored his Sicilian domains, and was content with allowing his German vassals more independence.
No idea on Japan. China however was organizing far, far larger armies. Greater population, more efficiency, and better organization.
The Italian city-states. During Frederick I's time, before the Battle of Legnano, Milan mustered 900 knights, and three other city-states mustered 550 more knights. They had like another 2,000 foot soldiers. So even arguably the richest city-state of the north, Milan, outside the Maritime powers, could only muster 1,000 knights alongside several times more foot soldiers. A decent force, but that was when they were being invaded and the HRE Emperors were trying to enforce their power over Milan and the other city-states. So if sending forces abroad, you'd likely see half of that number if lucky.
Later the Italian city-states started to rely on condottieri, who were professional mercenaries. It allowed them to employ professional forces for money, without needing to go through the process of training their own people for war. So by that point the numbers completely detached from typical medieval army sizes.
