“In fictional works, the king dramatically declares, ‘raise the army!’ or ‘call the banners!’ and then it mostly just happens.

But consider the complexity of the operation here: you need tens of thousands of men (without access to any kind of modern rapid or mass communication) to find out they have been selected (remember, many of them may not be able to read and you do not have a postal system anyway), then to transit to a muster point, acquire their arms, armor and equipment, divide into workable units for command and organization, have leaders selected and then pitch the army’s first camp.”

https://acoup.blog/2026/06/12/collections-pre-modern-armies-for-worldbuilders-part-iia-mobilization-without-administration/