This kingdom generator came from a combination of the following inspirational sources. I tried to take the best from each of them to make something solid yet simple for fleshing out the details of a Kingdom/Country. This process can be paralyzing when adding realism to your worldbuilding, but hopefully this helps you more easily figure out the who, what, where, and how many for your RPG. All numbers are generalizations and should be adjusted up or down to meet your needs.
Medieval Demographics Made Easy
The Domesday Book
A Magical Medieval City Guide
CrystalBallSoft's City Generator
Kingdom Generator
Square Miles
Enter the total inhabitable size of a kingdom/country.
People / Sq Mi
Select the population density.
Years
Enter the number of years the kingdom has been inhabitated by castle-building people.

People
Sq Mi
% Unsettled
People
Towns
Cities & Towns are urban centers. The rest live in rural villages, hamlets, and isolated groupings.
% Chance
The odds of having an academic university (not necessarily arcane).

Forts & Castles

Structures
Active
Active

Summary

Copy & Paste this text to keep for your worldbuilding.