Nomadic Tribe
Nomadic Tribes range in size and scale from tiny familial bands of perhaps a couple of dozen individuals to large nomadic communities of thousands, effectively comprising mobile societies that rival cities in terms of their power and influence and most notably their impact on trade. Nomadic tribes are often in conflict with neighbouring tribes, and also frequently raid threaten villages on the outskirts of controlled territories, threatening security and challenging development and expansion of organizaed society into the wilderness.
Among these tribes, shifting allegiances or power struggles lead to constant restructuring as leaders rise and fall. Occasionally these shifting dynamics allow a single tribe to consolidate power, absorbing neighbouring tribes and becoming an emergent regional power. This can put an enormous strain on resources over a large area and can draw such a horde into conflict with organized society, leading to the sacking and pillaging of entire cities.