The Barbarian tribes of Tarkazia are located in an environmental combination of steep mountains, forests, and rivers in the midlands of the continent. Each "tribe" is called a Steadfasting. Each Steadfasting is separated in the same way as the tribes of the Caucus mountains of the Transylvania area. Each Steadfasting is made up of different families but lacks the "Aristocratic" themes often seen in most barbarian and civilized tribes. They are more democratic than others. Each Steadfasting is "lead" by a small group of elected people, both male and female of various ages. The meetings are open to everyone who lives in a "Holdheim" within the boundaries of a Steadfast. (A holdheim is a house with permanent residents)
Age, Gender, or Class is not a concern for them. They are a merit-based society. They value strength not only in the arm but in the mind. So a great fighter is just as important as a weaver or farmer. Lineage is traced through the mothers. So a Barbarian's full name will reflect his mother, his Holdhiem, and his Steadfast.
The culture is more nature-based. In Agriculture, they keep sheep, goats, ponies, pigs, and Oxen (for plows not for food) rather than horses or cattle due to the environment. Major grains include barley, millet, and buckwheat. There is plenty of reliance on rivers for fishing. Hunting and gathering in the forest. Religion is more druidic and shamanistic. Bards don't travel as much as a traditional D&D bard does. Instead, they are more like local historians, who keep the history of their tribe alive in an oral tradition. Each Steadfast has a language, although neighboring Steadfasts will have similar words and dialects. But the further out you go from your Holdheim, the less likely it is you will understand the language. There is no official written language. But there are universal symbols shared by all the tribes. For example the symbol for good water (drinkable water), danger, boundary markers, food, currency and trade, and the numbering system.