The Hill Country is the most recently settled of the lands of the Three Realms. For many years, it was essentially unsettled and empty, mostly a little bit too far away to get attention from the Empires in the west: Baal Hamazi, Kurushat, and Tarush Noptii, although ancient petty kingdoms ethnically related to the Tarushans had once lived here. Little is known of the oldest of these other than their names, and their geographical boundaries are vague: Permia, Pezhek, Halych, Leszek, and Vuronezh. The romance of this unknown Kin Twilight, as its called, means that elements of those names sometimes pop up as people want to recall them by association. All of these were united in a larger kingdom near the end of this era that made up much of what is the territory of the Hill Country. Or at least the western portion of it from the shores of the Darkling Sea in the east to the Sabertooth Mountains in the West, and from the Plateau of Leng in the North to the eaves of the Thursewood and the Chatterwash River, where it bordered with its ethnically similar cousins in Tarush Noptii.  This large kingdom is Kinzassal, and while little is known about it directly, it is referenced in records from Tarush Noptii frequently. It collapsed before waves of Hamazin, Kurushans, and the Colonists from the east passed over the area; lightly in the case of the first of those two. The Kinzassians disappeared as a people, although its believed that many of them fled as refugees to merge with the people of Tarush Noptii or the Drylanders further north, and some few of them reduced to tiny hamlets of farmers, hunters and nomads still wandered the empty lands in tiny bands. It is believed that the majority of the genetic descent of the Tazitta people comes from ancient Kinzassal.

The Kurushans explored this territory, but never settled here. The Hamazin did establish some small settlements, and even had a few significant colonies, although they all failed long before the Baal Hamazi empire itself collapsed; wars in the Boneyards with Kurushat either cut off access to the colonies, or pulled manpower away from them. The evil and jagged ruins of ancient Hamazin castles and towers can still be found, often not far from ancient standing stones, henges and menhirs left by the Kinzassians or even the kingdoms that came before; or even ancient Atlantean ruins that belong to the non-human peoples that predated humanity. The territory went for centuries, or even millennia as mostly just empty wilderness until the coming of the Colonists from the east. 

The first wave to pass through were the proto-Timischers, who came from the land of Carlovingia far to the east. Few of them stayed in the Hill Country, as they set up their own new kingdom of Timischburg among the ruins of what used to be Tarush Noptii. However, Carlovingian peoples continue even now to pass through the territory; mostly homesteaders and new Colonists, leaving their homes forever to join their far-flung cadet group in Timischburg. Some of them don't make it all the way to Timischburg, as they find that the current version of the Hill Country is to their liking, and they settle there instead and assimilate with the locals.  

The next wave is the one that truly established the Hill Country as it's own. They also came from eastern kingdoms; especially Culmerland. The language and culture of the Culmers is the baseline that all others have assimilated to, although certain pockets still retain customs, cuisine or clothing from other eastern kingdoms. The Culmers are relatively well organized and peaceful; while capable in warfare, and willing to do it for many reasons, their natural tendency is to establish peaceful farming and ranching settlements and to get along well with their co-cultural neighbors. Those who came from Brynach, on the other hand, are a bit more fractious. While the Culmers are already pretty anti-authoritarian, the Brynachians are much more independent. In Brynach itself, they are less prone to peaceful homesteading, and often make up clans where low-grade raiding and warfare are common. Today, those who identify as more Brynachian as opposed to Culmerish are less likely to settle in the cities, and more likely to be on the frontier and the ranches where they can live a more active and adventurous lifestyle, and have fewer people trying to tell them what to do. (editor note: The peoples of the Hill Country are meant to evoke real-life European peoples, or diaspora Europeans like the Americans. Carlovingia is clearly supposed to be similar to the Carolingian Empire of the early middle ages, and the modern Timischers are similar to Austrians or Germans. The Culmers are Anglo-Saxons and the the Brynachians are the Celtic peoples of Britain, especially the Scots. The last two, which I'll cover shortly, are obviously Vikings and Normans, respectively. Keep in mind that in the modern day Hill Country, all of these elements are pretty mixed together; very few people would purport to be "Culmers" or "Brynachians" but rather simply Hillmen.) 

After its initial founding, many more people from Culmerland and Brynach have come to the Hill Country, but that's only because it's been many centuries. The flow of Colonists is a bare trickle. It's not just a question of an overland journey, however; there's only one route from the lands of the east to the Hill Country, and it is both difficult and dangerous. Those who come do so in small numbers, and come permanently.

However, a few other peoples have come from the east as well, in smaller numbers. Physically, they aren't terribly different from the mixed Culmerish and Brynachian sprinkled with Carlovingian, so they usually assimilate fairly well; although there are still small towns or neighborhoods where a non-Hillman ethnic identity is at least partially preserved. These are the people of Skeldale, who were famous as Reavers, but after their conversion to Christianity, they have become less of a threat and have embarked in more commercial enterprises.  In fact, more of them are coming from the east than any other people, although the absolute number of emigrants from the East is and always has been fairly small. By far the vast majority of people here are Hillmen, and have been here for many generations, and no longer identify with their ancestral stocks, but rather with their current situation. Another people who have a complicated history with most of the other nations of the East are the Normaunds. Militaristic and aristocratic, they find that their social position in the Hill Country has meant very little. Most of the Normaunds who have come to the Hill Country were third or fourth sons, or daughters who disliked arranged marriages, etc. so they assimilate better than you'd think, since their social position was not tenable in Normaund itself anyway.

The Hill Country resists central, federalized government, and few communities have any higher authority than a Lord Mayor, Council of "Important People", local pastors, and other residual landed gentry here and there. However, the region is divided in to two areas, and in each area, the communities see themselves as clients of one of two major cities. The boundaries between these two are not exact and are sometimes fluid as some communities make a bid to switch their allegiance, but they are more geographical than political, and today the political alignment just happens to correspond to the geographic one. The dividing line is the Umber River, which is what the Chokewater is called after leaving Waller's Wood. Southumbria is the more "pure" in terms of its government, and there is no central government at all. Far and wide, across the sub-region, people acknowledge the authority of the Lord Mayor of Barrowmere, and he does his best to help those across the territory. Indeed, to some he has specific obligations to do so. But these are a more localized and decentralized people. In Northumbria, north of the Umber, they acknowledge a more hierarchical structure based somewhat on the old countries to the East, although watered down. The Grand Duke of Garenport seeks to unite both Northumbria and Southumbria and declare himself King of the entire Hill Kingdom. Luckily for the Southumbrians, who want nothing to do with that, he's mired in political intrigues in his own territory, and his ambitions have had to be put on hold.

To be honest, few of the Northumbrians like it either. Although they have two political axes, the Hillmen see themselves as a single people, who have more in common in terms of culture and temperament than any other peoples, including even the stock populations of Culmerland and Brynach from which most of their ancestors hail, and neither the Northumbrians nor the Southumbrians have any interest in conflict for the political gain of Garenport elites.

A few new incipient regions are breaking off from these two main groups, including the expanding lands to the north of the Darkling Sea, and north and east of the Sabertooth Mountains. But those are incipient new areas; newly colonized wilderness, mostly, so they're not quite independent yet.

The purpose of the Hill Country is to be familiar, and yet also exotic in terms of it offering a form of adventuring "romance" that the real world has long since foregone.  What would it be like if Ivanhoe or Robin Hood era Britons came to a land that was much like the American frontier and established a new nation on it? And then make it more exciting and dangerous. The La Brea fauna isn't extinct; Columbian mammoths, sabertooths, dire wolves, and giant red lions are all over the place. And it's fantasy. Instead of dealing with hostile Indians, you've got the Tazitta Death Cults and the thurses, or beast-men lurking in the woods. Actual witchcraft and Lovecraftian and Gothic horror lurks in the corners.

The bigger cities and towns are several centuries old now, and fairly well established, and can offer a bit of urban intrigue and picaresque stuff, but the wilderness between them is wide and wild.