Also, they had mayors and stuff, a VERY clear class division and were technically under the rule of Gondor after the Northern Kingdom fell but Gondor didn't really have the resources or urge to do any ruling over there. Once Aragorn was in they were essentially an autonomous zone under military protection in exchange for maintaining the local roads and bridges.
It's a page-turner, but what no one ever says about it in the summaries is that it's like a geo-political spy thriller set in middle earth after the books. It's so good and not at all what I thought it'd be going in.
fucking baby-brained summary I expect nothing less from natopedia
on the plus side like 85% of the book is set in Umbar, and it's a pretty cool characterization of the city