The Northern Kingdom is half of the Lands of Men and ruled by kings who serve as benevolent monarchs with a ruling class made up of various lords, wizards and clerics.
The army is a combination of volunteers and sons/daughters who are not accepted into a trade school (magic or crafts, for example). They serve a term of 4 years, starting from 16.
Places of note:
See History of the Lands of Men for more information on the formation of the Northern Kingdom.